Reform of China social security system has made great achievements in constructing and revising the programmes for urban employees and poor groups,but new system remains unsettled and all social security policies need choosing. The ambiguous responsibilities of the subject in social security,too large a population of poor groups who need help from the programmes,the holes in a loose system and the disequilibrium of area development are among problems existed. The responsibilities of the subject should be made clear through legislating,the comprehensive city social assistant system and the social insurance policy be established,the sharing mechanism of social security responsibilities be further improved,and the rights of the rural labor and other mobile population by means of classifying them as different groups be ensured,and the construction of social security system in rural areas be actively pushed. A hole free secure net giving hope and substantial help to people is needed nowadays in China.