The effect of salinity and temperature on the settlement of the pacific oyster, Crassostrea gigas, was studied. Firstly, the activity of the competent pediveligers, eyed-larvae (348.6 ± 26.1 μm in total length), in seven salinities (10, 15, 20, 25, 30, 35 and 40 ppt) and six temperatures (16, 21, 25, 27.5, 30, and 35°C) were observed. The competent pediveligers were tolerable to wide salinity (10-35 ppt) and temperature (21-35°C). Secondly, the effects of five salinities (15, 20, 25, 30, and 35 ppt) and five temperatures (23, 26, 29, 32 and 35°C) on the settlement of eyed larvae were tested. The optimal salinity and temperature were 26-32°C and 15-25 ppt, respectively.