This research is on the relationship between corporate social responsibility (CSR) and corporate profit and growth. Specifically, how CSR makes firms more profitable is theoretically investigated with the methodology of system dynamics in this research. CSR becomes very important and essential in operating business within a society. many proponents have stated that CSR increases the firm's profitability and many researchers have made efforts on finding the positive relationship between corproate social performance (CSP) and corporate financial performance (CFP). However, CSR is a kind of cost with direct return in the accounting term so might be harmful to the healthy growth. Therefore, the effect network of CSR to the firm's business operations is investigated and discussed, and the existence of optimal CSR investment is investigated as well, in this research. The analysis results show that CSR styrategy should be implemented with the long term perspective and it is much better to perform CSR activities under consumers' high CSR perception circumstance.