In China hukou restriction which is often set according to the education or skill qualification of migrants virtually strengthens the selection of labor mobility. This phenomena of heterogeneous labor mobility has a profound influence on the geographic distribution of human capital and spatial pattern of modern industry, and thus affords a new insights for us to explain the formation and expansion of regional income disparity. This paper introduces hukou restriction in NEG model to analyze differential labor mobility with different skills, and the evolution trend of regional income disparity with different level of hukou restriction, trade cost and labor-human capital ratio. The results of numerical simulation demonstrate that due to pecuniary externalities low-skilled and high-skilled labor migration reinforce each other leading to agglomeration of both types of labor in the same region. But if raising the levels of hukou restriction or trade freedom, low-skilled labor remigrates, whereas high-skilled remains concentrated. The agglomeration of high-skilled labor becomes the major reason for the expansion of regional income disparity, which can be narrowed by improving regional integration, but maybe further widening if relaxing hukou restriction or raising human capital shares in the economy. This paper further reviews hukou restriction of some major provinces, the geographical distribution trends of human capital and the change of regional income disparity in China to give some empirical evidence.