Two cupped oyster species, Crassostrea hongkongensis and Crassostrea gigas are economically and ecologically important species native to the Northern and Southern coasts of China, respectively. C. hongkongensis is one of the most important oyster species currently cultured due to its high market value in Southern China. The species is distributed from Fujian to Guangxi Provinces, with populations centered in Guangdong Province. C. gigas is the most commonly species of oyster cultured, owing to its worldwide distribution, rapid growth, and dominant position in commercial oyster cultures. In Northern China, they are farmed primarily farmed in Liaoning and Shandong Province. To determine the possibility of transplantation of C. hongkongensis from Southern to Northern China, the early phenotypic traits both larval and juvenile C. hongkongensis and C. gigas were determined under the identical environments, which include temperature (Mt:(22±1.0) and Ht:(28±1.0)℃), and salinity (S₂₀:(20±1.0) and S₃₀:(30±1.0)) for larvae, and culture conditions (ID:In door condition and OD:Out door condition) for juveniles, at in Dalian, Liaoning Provincein July, 2007. The results showed that the shell width of C. hongkongensis was significantly larger than that of C. gigas (P<0.05), but the shell height of C. hongkongensis was significantly smaller than that of C. gigas (P<0.05). No significant differences in terms of shell length and fecundity (P>0.05) were found between the species. The egg-diameter, fertilization rate, hatchery successes, and the D larval size of C. gigas were all larger than those of C. hongkongensis. The larval growth of C. hongkongensis was smaller than that of C. gigas in during the early planktonic stage, but it was larger during the later planktonic stage under the same temperature and salinity. The order of two larval survival ability was:high temperature group > middle temperature group. The middle salinity group of C. hongkongensis larval size was larger than that of the high salinity group, and the high salinity group of C. gigas larval size was larger than that of the middle salinity group with at the same temperature. Larval metamorphosis was not only delayed, but it also larval metamorphosis was declined with decreasing temperature, the larval metamorphic size increased during the larval metamorphic stage under the same condition. Larval phenotypic characteristics were mainly affected by temperature, and the secondary factor was salinity, but mutual effects showed no positive action. The environment was the major factor for growth spurts during the juvenile stage and the phenotypic characteristics of spurts outdoors were better than those of indoors. The shell height of C. hongkongensis was significantly larger than that of C. gigas later on Day 60 (P<0.05). The survival rates of the two species of oyster species were over 90% during the juvenile stage, and there were no significant difference between the experimental groups (P>0.05) was found. Our analysis explicitly demonstrates that seeds of C. hongkongensis were successfully achieved, and their transplantation to Northern China may yield considerable benefits. It is propitious to supply the resource of C. hongkongensis, and also provide the scientific base on the interspecific hybridization between two oyster species in China.