Abstract: In order to study if cytoplasm of UV-irradiated heterogenous sperm affected the development of “fertilized” egg during gynogenesis, the embryonic development of Cynoglossus semilaevis haploid induced by UV-irradiated heterogenous and homogenous sperm were compared. The embryonic development course of haploid induced by UV-irradiated heterogenous and homogenous sperm was alike at the stages of blastodisc formation, 2-cell stage, multi-cell stage and blastula stage. After the stage of early gastrula, the developmental velocity of haploid embryo induced by UV-irradiated heterogenous sperm was slower than that of haploid embryo induced by UV-irradiated homogenous sperm. But, the morphology of haploid embryos induced by UV-irradiated heterogenous and homogenous sperm was alike at the corresponding stage. After stage of somite, the developmental velocity of haploid induced by UV-irradiated heterogenous and homogenous sperm was identical. A great deal of haploid embryos died after somite stage and the death rate of haploid embryos induced by UV-irradiated heterogenous sperm was larger than that of haploid embryos induced by UV-irradiated homologous sperm. The larvae hatched from haploid embryo induced by UV-irradiated heterogenous and homogenous sperm have haploid syndrome. The ploidy level of 30 gastrula embryos induced by UV-irradiated heterogenous and homogenous sperm was determined in order to verify that UV light completely irradiated sperm. The result of ploidy analysis showed that the embryos induced by UV-irradiated heterogenous and homogenous sperm were all haploid.