Abstract: The lowest social security system for urban and rural residents,with Chinese characteristics,is the social relief system, and is regarded as "the final safety net " in China' s soci- al security system.The minimal assurance system for urban and rural overall construction is necessary. It can help to maintain social fairness and justice,build a harmonious society,boost the economic development in rural areas and coordinate the economic and social development .It is also a need for reducing the cost of system operation and improving the current social security system.The minimal assurance system for urban and rural overall construction is feasible,considering the economic,political and practical basis.Minimal assurance system for urban and rural construction should comply with the unity of urban and rural understanding, the governmental responsibility and fund-raising in the urban and rural areas,the urban and rural minimal assurance management systems