Abstract: Pingxiang red-transparent crucian carp is a red and transparent mutant discovered from natural rivers in Pingxiang of Jiangxi Province, and has been identified to be triploid by DNA content measurement and chromosome analysis. In this study, the fine structures of chorion, micropyle, sperm entry site and plasma surface of its eggs were observed by SEM and TEM. In the meantime,the time sequence of sperm penetration,changes of the egg surface,cortical reaction,and formation and confusion of female pronucleus and male proucleus were also observed on two different mating groups.Group A is Pingxiang red-transparnt crucian carp(♀) × Pingxiang red-transparnt crucian carp(♂) ,and group B is Pingxiang red-transparnt crucian carp(♀)× Xingguo red comm.on carp(♂) .Similar processes on sperm penetration,egg surface change and cortical reaction were observed between the two different mating groups. The process of embryonic development was observed in the two different groups. Embryos can develop normally only above 16℃,and the optimal temperature for the embryonic development ranges from 20℃ to 25℃ . The data indicate that some differences exist in fertilization rate,hatching time,hatching rate and accumulate-temperature between the two different groups,and the water temperature is a main influence factor on the embryonic development.