There are many defects in researches on the relationship of the regional financial development (FD) and economic growth of China, such as simply assuming the causality direction, not highlighting financial institution, using incomplete financial indicator, etc. This article, taking Suzhou City of Jiangsu Province, China as a case, builds a simple model to study the level of FD from three aspects of financial scale, structure and institution. Three original indicators of PRIVY (private investment/aggregate investment), DEPTH (aggregate loan/GDP) and FDIVG (FDI/GDP) are used to construct the FD economic indicator through Principal Component Analysis approach. Then we use Granger method to analyze the relationship between the FD and the economic growth of Suzhou. Empirical test results show that the FD of Suzhou is the Granger reason of economic growth, while economic growth is not the reason for FD, because the relationship between the FD and the economic growth of Suzhou is just in the "supply-leading" period. In terms of Suzhou experiences, the local government should strengthen the protection of private investment, improve the institutional environment, and establish the reasonable financial structure. So we can concluded that FD could play a great role in promoting economic growth at the economy takeoff stage.