Abstract: In the agricultural economic structure of China in 2003, the Gross Domestic Product (GDP) was 117251.9*108 Yuan (by the comparable price of the year of 2000), in which the ratio among the primary industry, secondary industry and tertiary industry was 14.6:52.2:33.2; the gross output value of agriculture, forestry, animal husbandry and fishery was 16997.2*108 Yuan (by the fixed price of the year of 1990), in which the ratio among agriculture, forestry, animal husbandry and fishery was 48.6:5.0:33.8:12.6; and the total sown areas of farm crops was 15241.49*104 hectares, in which the ratio among gain crop, industrial crop and others was 65.2:16.2:18.6. According to the present situation of agricultural economical structure and the difference of the condition of water resources, the coming trend of the agricultural economical structure in the 3 regions of China in 2010 was analyzed in the paper, in which the annual increasing rate of GDP will be 8.2% for the eastern area, 7.1% for the middle area and 6.8% for the western area; the annual increasing rate of the gross output value of agriculture, forestry, animal husbandry and fishery will be 4.6% for the eastern area,4.3 % for the middle area and 5.7% for the western area; and the annual increasing rate of the total sown areas of farm crops will be a little.