Abstract: In this paper, by using the physical fitness data announced from the General Sports Administration of China, we test the mediation effect of peasants' income between the degree of urbanization and peasants' physical fitness.Under the control of the impact of natural environmental factors, there is a positive relationship between the degree of urbanization and peasants' physical fitness.Peasants' income plays a significant part of the mediating effect between the level of urbanization and peasants' physical fitness.This study not only gives the quantitative evidence of relationship between the new urbanization and peasants' physical fitness but also gives the empirical evidence of peasants' income transmission effect between them.