Gynogenetic diploids were produced from eggs of 10 female Rana rugosa by refrigeration after insemination with UV-irradiated sperm of 10 males of the same species. They were compared with the control diploids and gynogenetic haploids in developmental capacity. When refrigerated at 0∿2℃ for two hours after insemination with UV-irradiated sperm, 73.10f the eggs cleaved normally, and 65.1 0x1.5443cp+823nd 20.916032271143f these normally cleaved eggs hatched normally and became normally metamorphosed frogs, respectively. The diploidy of the individuals in the experimental series was confirmed by counting chromosomes at the tadpole stage. Of the 457 gynogenetic diploids, 418 were females and 39 (8.5%) were males. There were 931 females and 25 (2.6%) males among the 956 offspring of six gynogenetic diploid males mated with normal females. As the great majority of gynogenetic diploids and the offspring of gynogenetic males mated with normal females were females, it is assumed that the male is heterogametic in Rana rugosa and that gynogenetic males are genetic females. In the gynogenetic diploid tadpoles, there were 26 (2.4%) black-eyed and 23 (2.1%) gray-eyed mutants.