Abstract: Genetic variation of 26 stra ins of Cryphonectria parasitica from Korea, USA and Ch ina w as investigatedusing random amplified po lymorph ic DNA (RAPD) of genom ic DNA. 115 RAPD bandsw ere amplified by po lymer??ase cha in react ion w ith 12 random primers, and 61. 7% o f wh ich w ere polymorphic, the size of amp lified RAPDbands ranged from 0. 19 to 3. 1 kb. The lineage of 26 strains based on cluster analysis of RAPD bands, could beclassified as 1 b ig g roup and the big group inc luded 17 stra ins o fKo rea and 4 strains ofUSA. From th is resu l,t itw as show ed thatmost stra ins ofKoreaw ere sim ilar to each other, and also sim ilar to strains o fUSA, and the geneticre lationsh ip w ith stra in o f China w as very low.