To study the phylogenetic relationships of species of Trichaptum and to infer intraspecific dibergence of T. abietinum, partial mitochondrial small subunit rDNA sequences were determined. Six strains of T. abietinum, two of T. biforme, and one of T. fusco-violaceum were examined. Parsimony and distance analyses showed that each Trichaptum species forms a distinct group and that T. abietinum consists of two or more subgroups. Strains from North America were distantly related to one another but the European strain formed an independent group with three Korean strains, suggesting the possibility that Korean taxa may be phylogenetically closer to European taxa than to North American taxa.