Abstract: This article makes a new explanation concerning the function of educational investment to our economic growth from two aspects of total effect and overflowing effect. Furthermore, it makes an qualitative analysis by using Feder-model for reference and combing our historical data. From regression result, we can infer that output of non-educational sector will increase 1.3371 percentage through overflowing-effect of educational Investment when it is increased every one percentage by itself; output will increase as a percentage of 6.8 as the ratio of educational investment to GDP increases one point in percentage; Productivity of educational sector is lower than non-educational sector. In the end, it gives proposals and countermeasures concerning further enhancing educational effect and increasing educational input.