diff --git a/packages/select/src/select.vue b/packages/select/src/select.vue
index ed0258ae6..47719eda0 100644
--- a/packages/select/src/select.vue
+++ b/packages/select/src/select.vue
@@ -497,8 +497,8 @@
           let input = [].filter.call(inputChildNodes, item => item.tagName === 'INPUT')[0];
           const tags = this.$refs.tags;
           input.style.height = this.selected.length === 0
-            ? sizeMap[this.selectSize] + 'px'
-            : Math.max(tags ? (tags.clientHeight + 6) : 0, sizeMap[this.selectSize] || 36) + 'px';
+            ? sizeMap[this.size] + 'px'
+            : Math.max(tags ? (tags.clientHeight + 6) : 0, sizeMap[this.size] || 36) + 'px';
           if (this.visible && this.emptyText !== false) {
             this.broadcast('ElSelectDropdown', 'updatePopper');
           }