diff --git a/src/components/input/input.vue b/src/components/input/input.vue
index 045f7d57..79673eb2 100644
--- a/src/components/input/input.vue
+++ b/src/components/input/input.vue
@@ -90,6 +90,9 @@
             size: {
                 validator (value) {
                     return oneOf(value, ['small', 'large', 'default']);
+                },
+                default () {
+                    return this.$IVIEW.size === '' ? 'default' : this.$IVIEW.size;
                 }
             },
             placeholder: {