diff --git a/colossalai/inference/config.py b/colossalai/inference/config.py
deleted file mode 100644
index d274beb14..000000000
--- a/colossalai/inference/config.py
+++ /dev/null
@@ -1,7 +0,0 @@
-"""
-Our config consists of three parts:
-    1. model_config: The configuration for the model, including `model name`, 'model path' and self-defined layer.
-    2. parallel_config: The configuration for parallelize model, including `tp_size`,'pp_size', `world size`, `local rank`, `master port`, `master ip`.
-    3. cache_config: Configuration for initialize and manage kv cache, including `block size`, `block num`
-For the convenience of users, we provide a unified config api for that wrapped all the configs. One can easily construct a colossal_config by setting the needed configs.
-"""
diff --git a/colossalai/inference/core/config.py b/colossalai/inference/core/config.py
new file mode 100644
index 000000000..6b44dd7af
--- /dev/null
+++ b/colossalai/inference/core/config.py
@@ -0,0 +1,54 @@
+from typing import Optional, Union
+from dataclasses import dataclass
+
+import torch
+import torch.nn as nn
+
+@dataclass
+class InferenceConfig:
+    """The inference configuration.
+
+    Args:
+        model: Path or nn.Module of this model.
+        tokenizer: Path of the tokenizer to use.
+        tokenizer_mode: "auto" will use the fast tokenizer if available, and "slow" will always use the slow tokenizer.
+        trust_remote_code: Whether to trust remote code from huggingface.
+        max_batch_size: Maximum batch size.
+        max_output_len: Maximum output length.
+        max_input_len: Maximum input length.
+        block_size: The number of blocks in a logical block.
+        gpu_utilization_rate: Maximum GPU memory usage ratio.
+        dtype: The data type for weights and activations.
+        tp_size: Tensor parallel size.
+        pp_size: Pipeline parallel size.
+        max_seq_len: Maximum length of input sentence.
+        quant_mode: Quantization mode.
+        revision: The specific version(a branch, name, a commit id, or a tag name) of model to use.
+    """
+    
+    model: Union[str, nn.Module]
+    tokenizer: str = None
+    tokenizer_mode: str = "auto"
+    trust_remote_code: bool = False
+    max_batch_size: int = 8
+    max_output_len: int = 256
+    max_input_len: int = 256
+    block_size: int = 16
+    gpu_utilization_rate: float = 0.7
+    dtype: Union[str, torch.dtype] = torch.float32
+    tp_size: int = 1
+    pp_size: int = 1
+    max_seq_len: Optional[int] = None
+    quant_mode: Optional[str] = None
+    revision: Optional[str] = None
+
+    def __post_init__(self):
+        self._verify_args()
+
+    def _verify_args(self):
+        if self.gpu_utilization_rate > 1.0:
+            raise ValueError(
+                f"GPU utilization should be less than 1.0, but is set to {self.gpu_memory_utilization}."
+            )
+        if self.tokenizer_mode not in ["auto", "slow"]:
+            raise ValueError("Tokenizer mode must be " "either 'auto' or 'slow'," f"but got {self.tokenizer_mode}")
diff --git a/colossalai/inference/core/engine.py b/colossalai/inference/core/engine.py
index bf26b3ecb..7f78e9761 100644
--- a/colossalai/inference/core/engine.py
+++ b/colossalai/inference/core/engine.py
@@ -1,12 +1,14 @@
 from logging import Logger
 from typing import Optional
 
-from .request_handler import RequestHandler
+from transformers import AutoConfig
 
+from .config import InferenceConfig
 
-class InferEngine:
+
+class InferenceEngine:
     """
-    InferEngine is the core component for Inference.
+    InferenceEngine is the core component for Inference.
 
     It is responsible for launch the inference process, including:
         - Initialize model and distributed training environment(if needed)
@@ -15,37 +17,27 @@ class InferEngine:
         - Log the generation process
 
     Args:
-        colossal_config: We provide a unified config api for that wrapped all the configs. You can use it to replace the below configs.
-        model_config : The configuration for the model.
-        parallel_config: The configuration for parallelize model.
-        cache_config : Configuration for initialize and manage kv cache.
-        tokenizer (Tokenizer): The tokenizer to be used for inference.
-        use_logger (bool): Determine whether or not to log the generation process.
+        tokenizer: Path of the tokenizer to use.
+        inference_config: We provide a unified config api for that wrapped all the configs. You can use it to replace the below configs.
+        verbose (bool): Determine whether or not to log the generation process.
     """
 
     def __init__(
         self,
-        model_config,
-        cache_config,
-        parallel_config,
-        tokenizer,
-        use_logger: bool = False,
-        colossal_config: Optional["ColossalInferConfig"] = None,
+        tokenizer: str = None,
+        inference_config: Optional["InferenceConfig"] = None,
+        verbose: bool = False,
     ) -> None:
-        assert colossal_config or (
-            model_config and cache_config and parallel_config
-        ), "Please provide colossal_config or model_config, cache_config, parallel_config"
-        if colossal_config:
-            model_config, cache_config, parallel_config = colossal_config
-
-        self.model_config = model_config
-        self.cache_config = cache_config
-        self.parallel_config = parallel_config
-        self._verify_config()
+        assert inference_config, "Please provide inference_config."
 
         self._init_model()
-        self.request_handler = RequestHandler(cache_config)
-        if use_logger:
+        # cache_config may need to be modified later.
+        # self.request_handler = RequestHandler(cache_config)
+        self.tokenizer = tokenizer
+        self.hf_model_config = AutoConfig.from_pretrained(
+            self.model, trust_remote_code=self.trust_remote_code, revision=self.revision
+        )
+        if verbose:
             self.logger = Logger()
 
     def _init_model(self):
diff --git a/colossalai/inference/core/inference_struct.py b/colossalai/inference/core/inference_struct.py
new file mode 100644
index 000000000..331f0308a
--- /dev/null
+++ b/colossalai/inference/core/inference_struct.py
@@ -0,0 +1,169 @@
+import enum
+from dataclasses import dataclass
+from typing import Dict, List, Set
+
+
+class RequsetStatus(enum.Enum):
+    """The status of Sentences"""
+
+    WAITING = enum.auto()
+    RUNNING = enum.auto()
+    ABORTED = enum.auto()
+    OVERLENGTH = enum.auto()
+    COMPLETED = enum.auto()
+    LENGTH_CAPPED = enum.auto()
+
+    @staticmethod
+    def is_finished(status: "RequsetStatus") -> bool:
+        return status in [
+            RequsetStatus.OVERLENGTH,
+            RequsetStatus.COMPLETED,
+            RequsetStatus.LENGTH_CAPPED,
+        ]
+
+    @staticmethod
+    def is_running(status: "RequsetStatus") -> bool:
+        return status == RequsetStatus.RUNNING
+
+    @staticmethod
+    def is_waiting(status: "RequsetStatus") -> bool:
+        return status == RequsetStatus.WAITING
+
+
+class Sequence:
+    """Store information of input sequence.
+
+    Args:
+        request_id: The ID of input sequence.
+        prompt: The prompt of input sequence.
+        token_id: The tokens ID of input sequence.
+        block_size: The block size of input sequence.
+        sample_params: The sample_params of input sequence.
+        block_table_index: The index of input sequence in block_table.
+    """
+
+    def __init__(
+        self,
+        request_id: int,
+        prompt: str,
+        token_id: List[int],
+        block_size: int,
+        sample_params,  # SampleParams needs to be imported later.
+        block_table_index: int,
+    ):
+        self.request_id = request_id
+        self.prompt = prompt
+        self.input_token_id = token_id
+        self.blokc_size = block_size
+        self.sample_params = sample_params
+        self.output_token_id = []
+        self.status = RequsetStatus.WAITING
+        self.block_table_index = block_table_index
+
+    def get_sentence_len(self) -> None:
+        """
+        Get length of current sentence.
+        """
+        return len(self.input_token_id) + len(self.output_token_id)
+
+    def get_input_len(self) -> None:
+        """
+        Get length of input sentence.
+        """
+        return len(self.input_token_id)
+
+    def get_output_len(self) -> None:
+        """
+        Get output length of current sentence.
+        """
+        return len(self.output_token_id)
+
+    def check_finish(self) -> bool:
+        """
+        Check whether inference is over.
+        """
+        return RequsetStatus.is_finished(self.status)
+
+    def __repr__(self) -> str:
+        return (
+            f"Request ID(request_id={self.request_id}, "
+            f"prompt={self.prompt}, "
+            f"status={self.status.name}, "
+            f"sample_params={self.sample_params}, "
+            f"logical block number={len(self._logical_blocks)}"
+        )
+
+
+@dataclass
+class BatchHandler:
+    """
+    Information to be passed and used for a batch of sequences.
+    """
+
+    sequences_set: Set[Sequence]
+    block_table: Dict[int, int]
+
+    @classmethod
+    def init_batch(cls, seqs: List[Sequence]) -> "BatchHandler":
+        """
+        Initializes inference batches by input sentence list.
+
+        Args:
+            seqs (List[Sequence]): List of input sequence.
+        """
+        sequences_set = set()
+        block_table = {}
+        for seq in seqs:
+            if seq in sequences_set:
+                print("The sequence is already in sequences_set.")
+                assert (
+                    seq.request_id in block_table
+                ), "The sequence has been added to sequences_set, but it has not been added to block_table."
+                continue
+            assert (
+                seq.request_id not in block_table
+            ), "The sequence has not been added to sequences_set, but it is already in block_table."
+
+            sequences_set.add(seq)
+            block_table[seq.request_id] = seq.block_table_index
+
+        return cls(sequences_set=sequences_set, block_table=block_table)
+
+    def clear_batch(self) -> None:
+        """
+        Clear sequence set and block table.
+        """
+        for seq in self.sequences_set:
+            if not seq.check_finish():
+                seq.status = RequsetStatus.ABORTED
+        self.sequences_set.clear()
+        self.block_table.clear()
+
+    def fliter_batch(self) -> None:
+        """
+        Remove completed sentences from a batch.
+        """
+        for seq in self.sequences_set:
+            if seq.check_finish():
+                self.sequences_set.reomve(seq)
+                del self.block_table[seq.request_id]
+
+    def add_seqs(self, seqs: List[Sequence]) -> None:
+        """
+        Add new sequence to batch
+
+        Args:
+            seqs (List[Sequence]): The list of new sequences.
+        """
+        for seq in seqs:
+            if seq in self.sequences_set:
+                print("The sequence is already in sequences_set.")
+                assert (
+                    seq.request_id in self.block_table
+                ), "The sequence has been added to sequences_set, but it has not been added to block_table."
+                continue
+            assert (
+                seq.request_id not in self.block_table
+            ), "The sequence has not been added to sequences_set, but it is already in block_table."
+            self.sequences_set.add(seq)
+            self.block_table[seq.request_id] = seq.block_table_index
diff --git a/tests/test_infer/test_config_and_struct.py b/tests/test_infer/test_config_and_struct.py
new file mode 100644
index 000000000..580396e51
--- /dev/null
+++ b/tests/test_infer/test_config_and_struct.py
@@ -0,0 +1,37 @@
+from colossalai.inference.core.config import InferenceConfig
+from colossalai.inference.core.inference_struct import BatchHandler, Sequence
+
+
+def test_config_and_struct():
+    InferenceConfig("/llama")
+    sequence = Sequence(
+        request_id=1,
+        prompt="abc",
+        token_id=[1, 2, 3],
+        block_size=16,
+        sample_params=None,
+        block_table_index=1,
+    )
+
+    sequence2 = Sequence(
+        request_id=2,
+        prompt="bcd",
+        token_id=[4, 5, 6],
+        block_size=16,
+        sample_params=None,
+        block_table_index=2,
+    )
+
+    assert sequence.get_sentence_len() == 3
+    assert sequence.get_input_len() == 3
+    assert sequence.get_output_len() == 0
+    assert sequence.check_finish() == False
+
+    batch = BatchHandler.init_batch([sequence])
+    batch.fliter_batch()
+    batch.add_seqs([sequence2])
+    batch.clear_batch()
+
+
+if __name__ == "__main__":
+    test_config_and_struct()