According to the relevant data of China Statistical Yearbook and Chinese Rural Statistical Yearbook in the year of 2009, the changes of grey correlation degree of farmers’ net income, various items of incomes, national gross agriculture-supporting expenditure and various items of expenditures, farmers’ net income and various items of fiscal agriculture-supporting expenditure in the eighth Five-Year Plan, ninth Five-Year Plan and tenth Five-Year Plan by using grey correlation degree and the by choosing seven indicators covering income from wage and salary, income from household business, transfer income and property income, agricultural production-supporting expenditure, agricultural basic construction expenditure，expenses of three items of agricultural technology and the fee of rural relief. The results show that the grey correlation degree of each time period and household net income shows the downward trend; from overall perspective, the grey correlation degree of national gross agriculture-supporting expenditure, agricultural basic construction expenditure and agricultural production-supporting expenditure shows the descending trend; the grey correlation degree of fiscal agricultural supporting expenditure and the expenditure of three items of agricultural technology and fee of rural relief show the upward trend; the influence of agricultural production-supporting expenditure on farmers’ income shows downward trend; the influence of agricultural basic construction on farmers’ income shows upward trend; the fee of rural relief plays an active role in the promoting the farmers’ income increase; the role played by fee of rural relief in promoting farmers’ income increase should be further increased; the increase of farmers’ income shows great reliance on agricultural science and technology. In the end, the relevant suggestions on establishing stable increase mechanism of fiscal agricultural support and insisting on the dynamic adjustment of the structure of fiscal agricultural supporting capital are put forward.