Abstract: Based on stakeholder theory, agency theory, and social network theory, we find that Corporate Social Responsibility(CSR) could bring about investment opportunities to the enterprise, as well as promote manages' investment willingness. Thus we investigate the impact of CSR on firms' investment behavior. The results show that:Firms' CSR performance could significantly promote corporate investment. After partitioning the sample into growth, mature, and declining firms, we further find that the positive impact of CSR on corporate investment only significant in growth and mature firms samples, while the positive impact is not reflected so obviously among declining firms.