Abstract: Agricultural and the rural economy development cannot leave the fund assitting, the finance to the agricultural investment are important capital source of the“three agriculture”development.The paper using many statistical data analyzed the level of the fiscal policy for assisting agriculture with the economic society development,the financial revenue increasing of Zhejiang, but the level of financial assitting agriculture is still low,therefore it is vital to determine reasonably the scale of the financial assitting agriculture for the practical significance and the economical significance. The paper unifies the economic quantity model, has discussed the reasonable scale of Zhejiang finance assitting agriculture.