Four strains of Pacific white leg shrimp Litopenaeus vannamei，KonaBay，OI，SIS and Universal，with initial body weight of 1.00 g，were reared in 24 tanks of each 500 L at a density of 150 and 300 individuals per m2at water temperature of 28-30℃ and a salinity of 30-34 for 56 days to evaluate the culture performance of the imported Pacific white leg shrimp.Survival rate，total weight gain，wet weight specific growth rate，feed conversion ratio，and weight variation coefficient were determined as evaluation criteria.The best rearing performance was observed in KonaBay，higher or lower stocking density，indicating that the stocking density in the experiment is suitable for KonaBay.There was significantly lower survival rates of Universal an

d OI：strains at high stocking density than that at low stocking density（P＜0.05），without significant effect of stocking density on total weight gain，even degrowth at high stocking density in the OI（P＞0.05），indicating that both are not suitable for culure at high stocking density.In SIS，however，the survival rate，total weight gain，feed conversion rate of family were not significantly affected by high stocking density，and high stocking density led to reduce variation coefficient in body weight，the SIS showing more suitable for culture at high density.