Genetic variations in rice germplasm were investigated using RAPD and RFLP analysis. Seventy varieties of rice, including 31 Korean varieties, 18 Korean landraces, and 21 foreign accessions, were analysed. Seventy-three out of 273 RAPD and RFLP fragments were polymorphic among the seventy rices. The variation among the Korean landraces was lower than adapted modern cultivars, which was contrast to other reports. We detected several RFLP fragments which were present only among the Korean cultivars and foreign accessions but absent in the landraces. Therefore, these fragments were regarded as the DNA fragments which were introduced from foreign germplasm during the cultivar development by crosses between Korean varieties and indica typed foreign rice varieties. On the contrast with these fragments, one fragment was present among the landraces and foreigners but not in the Korean cultivars. This fragment was considered to be the DNA fragment that was screened out in the courses of cultivar developing programs. So, these RFLP fragments could be useful in rice breeding program if they are related to agronomically important traits. The genetic variation among the indica rices was higher than that of japonica rices and the japonica rices were differentiated from the indica ones at the similarity level of 0.75.