The spermatogonial metaphase of 2 subgenera, 7 amphidromid species from several parts of Thailand were analyzed by air-drying techniques. All species have the same haploid and diploid chromosome number, n=29 and 2n=58. The karytypic pattern of subgenus Amphidromus and two species were investigated. The result show that A. (A.) atricallosus and A. (A.) inversus are different in chromosome structure. A. (A.) inversus composed of metacentric, submetacentric and subtelocentic chromosome, whereas A. (A.) atricallosus composed of metacentric and submetacentric chromosomes only. However, the karyotypic data of the subgenus Syndromus is in adequate due to the poor of the metaphase cells obtained.