The earth has been facing a rapid warming during past several decades. To figure out the impact of high temperature on agronomic performance of rice especially on yield, we cultivated 89 rice varieties of various origin in Suwon Korea, Shanghai China and IRRI Philippines(Wet season and Dry season). Days to heading, culm length, panicle length, panicle number, spikelet number, spikelet fertility, grain weight and grain yield were comparatively investigated. Overall grain yield displayed significantly lower values in Shanghai and IRRI(wet and dry) compared with in Suwon. Meanwhile minimum values were much lower in Shanghai and IRRI than in Suwon. However, some varieties such as Keunseom, Taichung178 showed similar performance for grain yield in both Suwon and IRRI(wet season), and some varieties such as Hangangchal, Dasan showed similar performance for grain yield in Suwon, Shanghai and IRRI(wet season), Nampung showed very high yield in Suwon comparing to other two locations. For most varieties, grain yield was the highest in Suwon and followed by in Shanghai and at IRRI(wet season). However, in dry season at IRRI, yield trend was quite different from the expectation. Further studies are in progress to find out the genotype by environment interactions in order to obtain basic information for breeding high temperature tolerant rice.