In general，the current difficult population in urban and rural areas in China is still at a large scale，and most of them are the sick，the elderly，the disabled and the unemployed population. For this population，their health condition is not good；and they have the tendency of controlling the healthcare expenditure. Meanwhile，they have low education level，and they face the pressure of their children’s education expense. From the economic perspective，their household income and expenditure level is significantly lower than ordinary people. And with regarding of housing，the government sponsored housing policy is very important to them. They also have heavy household expenditure burden and experience informal employment. Regarding their social mentality，some of them experience problems of mental health. They tend to hold personal responsibility of their condition，and their sense of social injustice and lack of control is relatively strong. Further，they have high willingness of social participation，high social trust，and low social discrimination at the community level. When it comes to policy evaluation and appraisal，other than meeting day-to-day needs，they have strong request of social aid in medical expense，education expense，and job seeking service，which are the reason why they apply for government assistance program. They have high evaluation and needs for medical assistance program coupled with low income household assistance program，while low percentage of request and moderate evaluation are given to education assistance program. The paper emphasizes the need for the improvement of medical and education assistance program，coupled with temporary assistance program. And both government sponsorship and individual responsibility should be strengthened. Meanwhile，how to define difficult population should be studies in order to enhance the management and function of the comprehensive social assistance system.