Different types of japonica rice were tested in Jiangxi Province to see which varieties performed best in different regions. Overall, hybrid japonica rice yielded more than conventional japonica rice, with late japonica rice performing better than semilate japonica rice. Late hybrid japonica rice from Zhejiang Province had the highest yield in Xinjian, Fuzhou, and Ji'an sites. The best sowing date for high yield was 30 May in Xinjian and Fuzhou, and 9 June in Ji'an. The Poyang Lake plain and areas north of it were found to be suitable for planting japonica rice in Jiangxi Province, with late hybrid japonica rice from Zhejiang Province being the optimal variety.