Abstract: Agriculture is the industry that would be seriously affected by weather, and climate change would have profound impacts on crop productivity and planting structure. To make clear this problem, this paper set several scenarios considering temperature changes, precipitation decline and CO2 concentration increase, and build a DNDC—CGE model of China to simulate them. The results show that temperature rise will increase the unit yields of most crops, but market supply-demand discipline would make their prices float reversely, which change framers’ behavior, transferring farmlands to plant other crops which price would be increased by the marker forces. Precipitation decline will decrease most crops’ yields, especially sugarcane and potato, and the planting area, price and added value of rice and grain will decrease. On the other hand, CO2 concentration increase will increase most crops’ yields, but it is unbeneficial to fiber crop’s production increase. In total, Climate change is good for the GDP growth of China.