The polyacrylamide gel plate electrophoresis was used to study thedifferences and genetic tendency of lactate dehydrogenase(LDH), malate dehydrogenase(MDH), esterase (EST), and superoxide dismutase (SOD) of Xinghuai hybrid cruciancarp and its parents. The tissues used in the experiment are eye (lens), brain, muscle,heart, liver, and kidney. The results showed that the LDH isozyme of Xinghuai hybridcrucian carp expressed more dominantly the characteristics of fatherly isozymes. TheMDH and EST of Xinghuai hybrid crucian carp expressed more dominantly the chara-cteristics of maternal isozymes. The SOD isozymic patterns of eye, heart and kidney ofthree fishes were similar, But the SOD isozymic patterns of liver, muscle and brain ofXinghuai hybrid crucian carp were different from its parents. All isozymes of the testedfishes expressed, in some degree, the tissue specificities. In addition,the isozymic patternsof Xinghuai hybrid crucian carp demostrated a new hybrid enzyme band and a comple-mentary enzyme band which were not found at the isozymic patterns of its parents. Theisozymic patterns of Xinghuai hybrid crucian showed self-specificity. Nearly all studiedisozymes of Xinghuai hybrid crucian carp owned higher active than that of its parents.