Abstract: The yield and yield components of medium indica rice from regional trials in 7 main rice producing provinces (including Jiangsu，Zhejiang，Anhui，Sichuan，Hunan，Hubei and Jiangxi)were analyzed．The results showed that the direct contribution rate of grain number per panicle to yield was greater than that of productive panicle number per plant and 1000-grain weight，indicating the key point to improve rice yield was to promote the number of grains per panicle as far as possible．In field production，the seedling density should be increased to ensure the number of productive panicles per plant and then to promote the number of grains per panicle．

Key words: rice, yield component, regional trial