Abstract: To study the effect of climate change on grain production, consumption and economic growth, using grain production and climate changes in previous researches, policy schemes in base period were simulated, grain production, consumption and economic growth by 2050 in China were predicted based on the computable general equilibrium (CGE) model. The results showed that (1) by 2050, under the high carbon emission scenario (A2), the total grain yield was 629185 thousand tons, and the total consumption demand was 626609 thousand tons; under the medium and low carbon emission scenario (B2), the total grain yield was 601859 thousand tons, and the total consumption demand was 561093 thousand tons. Without regard to the loss and inventory, the supply and demand of grain was basically in a balance with supply slightly bigger than demand. (2) When taking the fertilizer effect of CO₂ into consideration, climate change would have positive effects on China’s macro and sector economy by 2050. Macroeconomic indicators such as real wages, real GDP, investment and household consumption and export all increased compared with that of the base period; from the aspect of sector economy, climate change also had positive effects on the output, consumption, import and export of the primary, secondary and tertiary industry. However, the results were opposite without considering the fertilizer effect of CO₂. (3) The positive effect of climate change on China’s macro and sector economy under A2 scenario was higher than that under B2 scenario. (4) Considering the effect of climate change on grain yield and demand, when taking the fertilizer effect of CO₂ into consideration, grain supply increased and import reduced under both A2 and B2 scenarios, and the increased supply quantity was larger than that of the demand. Therefore, taking the fertilizer effect of CO₂ into consideration would guarantee the supply and was beneficial to food security in China, while without considering the fertilizer effect of CO₂, the results were opposite.