Abstract:Based on GTAP model,the impact of directed technological change on China’s food security is examined with grain output and nutrient supply per capita as food security indicators. The result shows that the direction of agricultural technological change is crucial to ensuring food security. In terms of agricultural production,all directed technological changes are favorable to the increase of agricultural outputs,among which the effect of land-augmenting and unskilled labor-augmenting technological change is the most significant. Further classification of unskilled labor shows that farming and other unskilled labor-augmenting technological change has the most significant effect on increasing agricultural output. In terms of changes in nutrient supply per capita,the impact of directed technological change in agricultural sectors on nutritional supply is different. The land-augmenting and unskilled labor-augmenting technological change has the most significant impact on the per capita nutrition supply,while the impact of water-augmenting technological progress on per capita nutrient supply is insignificant. In the scenario of subdividing unskilled labor,among the three types of unskilled labor-augmenting technological change,the farming and other unskilled labor-augmenting technological change has the most significant impact on the per capita nutrition supply. Therefore,to ensure food security in China,technological change in agriculture should be directed towards improving the productivity of land and unskilled labor.