Acute low income of farmers and big difference of income between city and countryside are obvious manifestation of AFC issues in our country. For building moderately and harmonious society, we must solve the problems of A.F.C. thoroughly. This article has analyzed the nature of A.F.C. problems and pointed out that the key how to solve A.F.C. problems is reducing the quantity of farmer in a large number and carry out the strategy of Urbanization. Urbanization is not only the key of AFC problems, but also it is a consequential process and choice for building moderately and harmonious society.