The former working class, peasantry and intellectual in China have changed considerably since China implemented the policy of reform and opening to the outside world. Some new social strata appear, different classes and strata intersect and infiltrate each other and take shape a complicated situation. The primary factors that affect above-mentioned changes are the development of social division of labor, the formation of market economy, the changes of relation of production and the influence of policy. It is very important for our socialist modernized construction to recognize and treat these changes objectively and comprehensively and settle relations among various classes and strata properly.