Compared with the international standard and China's development aim,there exists obvious departure problems in the composition of public expenditure in China.This paper analyzes this problem from the angle of system.We construct an endogenous growth model containing corruption index and public expenditure,which shows that corruption would affect the composition of public expenditure because of the different difficult degree of corruption in different type of public expenditure.Based on the empirical evidence in China from 1995 to 2004,it says that corruption reduced the proportion of the expenditure of social culture and education.We must increase the management of corruption in order to improve the composition of public expenditure on a continuable base.