Abstract: In this paper the effects of salinity on the rata for embryonic de-velopment of oyster OsErea tcad2enw3xaneasis Cxosse3 and on the growth of the veli-ger are reported At the temperature of 21.2and the salinity of 31，26,the time ofthe embryarxic development from fertilised egg to straight hinge larvae is nineteenhours and thirty minutes. The effective salinity range of the embryonic developmentof the oyster is 17-39% and the optixrum salinity range is 22--34%,x. Within thesalinitp range of 22-36%，the rate of the embryonic development is faster, andthe mean time of the embryonic development is no more than twenty hours. The developmen willb delayeden saliniy 900ztime of the embryonic development vQill be delayed when salinity goes beyond thebounds of the optimum range. Within the salinity range of 25.21-34.25%,the rateof growth of the veliger is faster，the daily growth of the larvae is 8.54-9.38 umand the veioeity of the survival of the veliger is higher (the mean percentage isabove 50%). When salinity goes beyond the hounds of the optimum range, therate of the growth and. the survival of the larvae will be lower.