The present paper compares karyotypes and zymograms on three species of abalones Haliotis planata, H. varia, and H. diversicolor diversicolor collected from coasts of Japan. The diploid chromosome number was 32 in all the three species, comprising 18 metacentric, 12 submetacentric and 2 submeta- or subtelocentric chromosomes both in H. planata and H. varia and 16 metacentric, 14 submetacentric, and 2 subtelo- or acrocentric chromosomes in H. diversicolor diversicolor. Zymogram analyses revealed interspecific differences with regard to presence or absence/mobility of some loci coding six enzymes as well as intraspecific genetic variations. Hardy-Weinberg analyses on genotypic distribution indicated some excessive occurrence of homozygotes at some loci, suggesting inbreeding structure in the wild populations sampled.