Abstract: 【Objective】 This study aimed to identify the structural impacts of tariff concessions under the Regional Comprehensive Economic Partnership （RCEP） on key agricultural products in China， providing a reference for establi-shing an open-oriented food security system under the new pattern of opening-up. 【Method】 Based on the actual tariff commitment schedules signed under the RCEP， the actual levels of agricultural tariff concessions among RCEP members were calculated. The impacts of tariff concessions under the RCEP on China’s import patterns for agricultural products such as rice and wheat were stimulated and analyzed based on the GTAP model. 【Result】 After the RCEP took effect， the absolute magnitudes of China’s tariff concessions on agricultural products including fruits and vegetables， sugar products， animal products， and dairy products for other RCEP member states were relatively large， followed by concessions on oilseeds and oils ， while tariff concessions on wheat and rice remained at the original level （65.0%）. The import tariff rates of agricultural products set by other RCEP member states for China were generally low， showing a regional pattern of Japan/Korea>ASEAN countries>Australia/New Zealand， and a product structure of rice>dairy products>sugar products> fruits and vegetables>aquatic products>other cereals>wheat. These rates declined as the RCEP agreements were implemented. Tariff concessions under the RCEP led to comprehensive growth in China’s imports of major agricultural products， especially rice， wheat， and animal products； China’s imports of agricultural products increased significantly from most other RCEP member states， with moderate growth also observed from non-RCEP member states， although the growth rates gradually declined. In the 1^st， 10^th， and 20^th years after implementation of RCEP， the growth rate of China’s agricultural imports from the US， EU， and other countries or regions decreased from 28.3% to 24.4%， from 30.4% to 22.3%， and from 22.1% to 17.9%， respectively. The tariff concessions under the RCEP broadened China’s agricultural import sources to some extent and enhanced the domestic supply capacity of major agricultural products， but the substantial increase in rice and wheat imports would create competitive pressure on domestic grain production， posing new challenges to China’s import management of rice and wheat and the food security goals. 【Suggestion】The grain supply should be stabilized through regional agricultural cooperation， and RCEP agricultural collaboration should be deepened via supply chains， technology， and policy coordination. Grain import risks should be mitigated by leveraging the international agricultural trade rules， and the import management and production support for rice and wheat should be strengthened to safeguard the bottom line of food security for China.