Mitochondrial DNAs has been used frequently as genetic markers for the population genetic studies of salmonid fishes. Samples used in this experiment were chum salmons (Oncorhynchus keta) from Korea. We analyzed variation of mitochondrial NADH dehydrogenase subunit 3 gene (ND3) among 4 individuals of the Korea population. Genomic DNA was extracted from the liver of the chum salmon samples. Then, the ND3 gene was amplified by polymerase chain reaction (PCR) including the 3`region of cytochrome oxidase III gene (COIII) and the 5`region of NADH dehydrogenase subunit 4L gene (ND4L). The size of the PCR product was 752 bp and the sequences showed some genetic variation among those four individuals. Genetic variations were observed in 7 sites as single nucleotide polymorphism (SNP). Within the open reading frame of ND3 gene which encodes 116 amino acids, 5 nucleotide substitutions were found. Both transitional and the others of a Japanese chum salmon in Genbank showed 5 sites of SNPs. This study provided the basic information of SNP in ND3 gene among Korean chum salmons and demonstrated the possible use of the SNP data as a genetic marker.