Abstract:Resistance of 13 chestnut cultivars(Castanea spp.) to Cryphonectria parasitica in Korea was determined by the rapid testing method. Five chestnut cultivars are resistant, five cultivars susceptible and three cultivars moderate resistant (or susceptible).The genetic variation was investigated by the random amplified polymorphic DNA(RAPD), 12 random primers were selected in RAPD analysis, 100 polymorphic RAPD bands were amplified, but the peculiar RAPD band which discriminates between resistant and susceptible cultivars could not be detected. For the linkage result of cluster analysis, 12 cultivars could be classified as the resistant, susceptible and moderate resistant (or susceptible) groups approximately, which are almost coordinated to the above rapid testing results. The genetic relationship between one resistant cultivar and other 12 cultivars is very low. These results suggest that the primers selection of genetic regions related to resistance will be effective for the research of genetic variation and identification of resistance in chestnut.