Abstract: In order to solve the problems in the cultivation of the Patinopecten yessoensis, a crossbreeding experiment was carried out between P. yessoensis and P. caurinus. Two hybrids, P. yessoensis(♀)×P. caurinus(♂)(PY♀×PC♂) and P. caurinus(♀)×P. yessoensis(♂)(PC♀×PY♂), together with purebred P. yessoensis and P. caurinus were produced. The PY♀×PC♂ cohort outperformed both pure-bred parental cohorts in both larval and juvenile growth with medial performance in fertilization rate, hatching rate and larval survival rate between two pure-bred cohorts. The PC♀×PY♂ exhibited negative hetereosis in fertilization rate, hatching rate and larval growth, as well as in survival rate. It seems that the origin of eggs had significant influence on performance of hybrids. The results thus suggest that it is possible to improve the stock of the local Japanese scallops by hybridizing them with P. caurinus.