Square City system was consistent with " encouraging agriculture supressing commerce " policy and consolidated the ruling needs to facilitate the management of the ruling class while met the feudal bureaucratic system. But it presented as obstacles and constraints in terms of economic development due to the existence of Square City, a fixed time and fixed place of trading. Traders ignored the external packging of goods. However, the rapid development of commodity economy in mid-Tang dynasty brought about the collapse of the system. In a free and prosperous market economy with the background of enriching production resources, the packaging for protection and transport increased together with categories of goods. people also began to demand outside packaging utility for decoration and protection. The technology development propelled by economic development also promoted the packaging development.