The strict census register management system and dual insurance system between cities and countryside make urban and rural residents have unequal social insurance treatment,result in separation between cities and countryside,hamper the flow of surplus rural labor to cities,and have delayed urbanization process of China.In order to meet the dement of urbanization,construction of unified social insurance system is the final objective of social insurance of China.China should reform census regiater system and reform and consummate rural and urban social insurance system.