On the basis of CGSS2006 data，using Regression-based inequality decomposition technique，the paper compares the contribution of human capital，political capital and social capital on the income inequality of Chinese urban residents between the eastern and midwest . The total impact of human capital on inequality of china has slight difference. In which the level of education in the eastern affects income greater than midwestern. experience is the opposite. Impact of social capital of midwestern urban resident on inequality，by contrast，is more than the eastern, but the impact of political capital on income inequality is greater than in the eastern. Refuting market monism of income inequality，this paper considers that the role of the market and the state all have impact on income inequality.