Abstract: Capital is the most factor in the economic increase, even if the use of technology hassomething to do with it. To the western regions of china, the role, which capital contributes to the economy development, is greater than technology. This article regresses the private investment and the western development by the statistical soft-wear-SPSS (11.0). The regressive results show that the two has a strong correlation.Thus, under the circumstance of capital shortage in the western regions, the success of exploiting the western regions will depends on the private investment.