This paper investigates the significance of human capital and conducts regression on marginal productivity of capital with several factors based on the provincial data from 1978 to 2015. The object of study is mainly classified into three groups as eastern, central and western areas, so as to find out evidence of east-west economic gap and offer some useful data in improving western economic growth problem. We find that human capital is of significance in production function with embodied technology improvement. Combined factors' growth rate per year with their returns to MPK, we compare three areas factor contribution to MPK and affirm the importance of improving human capital investment to increase local MPK.