Eight Chinese and Korean indica cultivars including Dianchao 1, Dianchao 3, Guichao 2, Dasanbyeo, Milyang 23, Samgang-byeo, Yongmoonbyeo and Nampungbyeo were employed to inverstigate the yield potential of indica rice cultivars in Binchuan county (subtropical zone) of Yunnan province in China and Suwon (temperate zone) in Korean from 2001 to 2002. The results showed that the average grain yield and yield potential of these cultivars in subtropical zone were over 1.25 t/hm2 and 4.43 t/hm2 respectively, which were more than those in temperate zone and were significantly existing 1% probable level. Spikelets and dry matter played an important role in the grain yield potential in different ecological zones. 20 000 spikelets per square meter and 422.25 g/m2 were more in subtropical zone than in temperate zone. The rank of yield factors for yield were the number of panicle＞spikelets per panicle＞seed setting rate＞1 000-grain weight in subtropical zone while ranked as 1 000-grain weight＞spikelets per panicle＞the number of panicle＞seed setting rate in temperate zone. Therefore, the rice grain yield could be increased, by properly reducing grains of panicle and improving seed setting rate in subtropical zone and it is also most likely to improve spikelets per panicle and 1 000-grain weight in temperate zone.