Analysis of phylogenetic relationship was performed among Phellinus species based on 18S ribosomal subunit sequence data. Twenty-five strains of 19 Phellinus species including P. linteus were examined in this study. Regions of 18S ribosomal subunit were very conserved, but some variable regions between Phellinus species were observed. The species-specific detection primers, modified by 2 or 3 nucleotides in sense primer were designed based on 18S ribosomal DNA(rDNA) sequence data. The 210 by PCR bands were detected with annealing temperature $48^{circ}C$. The 18S 2F-18S 4R detection primer set distinguished P. linteus from various Phellinus species but some species like P. baumii, P. weirianius, P. rhabarberinus and P. pomaceus also had weak reactivity on this primer set. The 18S 3F-18S 4R primer set distinguished only P. linteus from various Phellinus species, although sensitivity with this primer set was lower than that of 18S 2F-18 4R primer set. These primer sets would be useful for the detection of only P. linteus among unknown Phellinus species rapidly.