Ploidy levels and chloroplast DNA (cpDNA) of Actinidia taxa distributed in Japan were investigated. Actinidia arguta in northern and southern Japan was tetraploid, while one plant of A. arguta and all accessions of A. arguta var. hypoleuca were diploid. All A. polygama distributed in Japan were diploid. PCR-RFLP analysis of the rbcL region of chloroplast DNA (cpDNA) allowed to classification into three genotypes. Genotype I was found in A. arguta plants distributed in the northern Japan and genotype II was found in A. arguta and A. arguta var. hypoleuca distributed in the southern Japan. Genotype III was detected only in A. polygama.