Abstract: With the relationship between informal finance and rural economic growth in China as a starting point, this paper made an empirical research on the relevance between informal financial development scale and rural economic development with Chinese data from 2004 to 2013 based on vector auto-regression model (VAR).The results of Grange Causality Test showed that informal finance and rural economic growth were Grange causes for each other. The informal finance played a promoting role on rural economic growth, but also had problems of inadequate space for development, lack of standard, inadequate policy support, etc. On the basis of this, the author put forward proposals like improving the legal and institutional guarantee of informal finance, strengthening the internal control of informal finance, increasing the policy support to informal finance and the absorption of foreign informal finance development experience.