Abstract: The protein and isozyme phenotypes of diploid and allotriploid hybrids of female silver carp譵ale bighead carp and female silver carp譵ale blunt snout bream, autotriploid silver carp and their parental species were analysed by gradient gel electrophoresis on polyacrylamide. The gene expression of diploid F1 hybrids was variable, and the variable expressions might be related to the phenotypic difference in proteins and isozymes in both parental species. In comparison with diploid F1 hybrids, the phenotypes of muscle proteins and serum proteins were basically identical in the allotriploids of silver carp and bighead carp. In addition, the phenotypes of EST and MDH in both allotriploids were close to those of maternal silver carp. These results suggested that the gene expression of allotriploid should be close to the maternal species and have a stable and identical tendency due to the increase of one maternal genome. The phenotypes of muscle proteins, serum proteins, G3PDH, MDH and LDH isozymes were not different between autotriploid and diploid silver carp.