The combined effects of water temperature and salinity on the settlement rate and density (spats/cm2) of Crassostrea gigas pediveliger larvae were studied under the hatchery conditions. Four water temperatures (20.0, 23.0, 26.0 and 29.0℃) were tested at three salinities (20.0, 30.0 and 40.0). The optimum water temperature by salinity conditions were 29.0℃ and 20.0, 30.0 which significantly (P ＜ 0.05) the highest mean (±S.D) larval settlement rate of 43.1 ± 0.1%, 42.1 ± 0.1%, respectively. But the combination of water temperatures and salinities for settlement density was not effected, but each factor as water temperature (29.0℃), salinity (40.0) was shown significantly high and low settlement density, respectively (P ＜ 0.05). The statistics result of settlement density frequency was appeared: mode (1.2-2.3 spats/cm2), Mean (1.9-2.4 spats/cm2), Range (3.0-5.8 spats/cm2) and the lowest variance was obtained 0.4 at water temperature 20.0℃ by salinity 30.0, but 29.0℃ by 20.0 was the highest (1.1). The best condition at this results for the larvae setting under the artificial seed collection of C. gigas was 29.0℃ and 20.0-30.0.
