Corrugated boxes for frozen foods can be very easy to collapse in refrigeration process. It was put forward that the cause of collapse is decrease of mechanical property of corrugated box. The causes of mechanical property decrease were analyzed through frozen storage experiments of corrugated boxes. The results showed that the cause of mechanical property decrease of corrugated box is the state change of water in corrugated box; moreover, increasing of moisture content and the change of the adhesive properties are the influencing factors.