R&D investment possesses lots of risks, which will lead to the increase of capital cost and raise the burden of R&D financing. Consequently, this will produce some negative influence on the positivity of R&D. Based on the data of Chinese A-share companies from 2007 to 2013, this paper is devoted to the study of the impact of the effects of the R&D capital cost and corporates' governance mechanism on the relief of the capital cost of R&D investment. We find that there exist significant positive correlation between R&D investment and the cost of equity capital. And the effect on the R&D investment is very distinctive. In addition, we also find that the increase of the stockholding ratio among senior manager, board of directors and board of supervisors will be helpful to reduce the capital's effect on the R&D investment. Furthermore, the extent of companies' information disclosure plays a crucial substitution role of decreasing the impact of the R&D investment produced by the stockholding of senior manager. The increasing of the yield rate brought by the R&D investment will instead contribute to offsetting the improvement of the cost of equity capital which is induced by the R&D investment.