In this article，based on data of One Belt and One zone countries between year 2003 and 2014，we improve a basic model of economy growth and focus on studying the influence of institution and FDI inflow on those countries’ economic growth. The result of our regression model indicates that institution，which plays a very positive role in the growth effect of FDI inflow，is the inner motivation of economic growth. But，Institution functions in different countries with different institution systems may differ. Comparing with those developed and developing countries，the transitional countries get higher and stable contribution rate of economic growth from their institution. Their growth effect of institution in FDI inflow decreases in the beginning and then increases in the end. Furthermore in the end of this article，we give some useful advices for the institution system arrangement and inflow paths of China’s FDI in One Belt One Zone countries.