[Aims] Lentinula edodes (Berk.) Pegler has many commercial strains both morphologically and physiologically similar to each other. At present, detection of polymorphism in rDNA-IGS region (Babasaki, 2006) and/or RAPD marker (Zhang and Molina, 1995) is generally used for strain typing of L. edodes. However, it is rather time-and-cost consuming. Inter-retrotransposon amplified polymorphism (IRAP)-PCR method mainly used for horticultural crops takes less time and lower in cost in strain typing (Kalendar et al, 1999). In this study, we designed IRAP primers for L. edodes and verified their strain typing efficiency. [Method] Thirty three strains were provided for this study. Either fungal cultures on PDA or fungal tissues of fruit bodies were cut into approximately 4 x 4 x 4 mm. Total DNA of each samples were extracted by DNeasy Plant Mini Kit (QIAGEN). For PCR, IRAP primer set and Pfu-X polymerase (greiner) were performed. Based on LTR (Long Terminal Repeat) sequence in L. edodes, we designed one set of primers amplifying the regions between retrotransposons. Ampricons were electrophored for 50 min at 100 V on 1.7 % agarose gel with GelRed (Biotium) and evaluated under UV irradiation. [Results] The products obtained by IRAP-PCR were determined using mini-gel electrophoresis system. The band patterns of IRAP-PCR products differ among strains except the ones having the same parental cultivar. The detected bands were bright and clear without smearing. The IRAP-PCR products of fungal cultures on PDA and correlating fungal tissues of fruit bodies showed the same band pattern, suggesting that the procedure is highly reproducible. Thus, it is considered that IRAP-PCR with short ranged (ca. 1 kb) electrophoresis is a time-efficient and practical strain typing method of L. edodes.