The lipid and fatty acid composition of the pearl oyster Pinctada fucata,in different shell length specifications,in different condition index and in various tissues which were adductor muscle,mantle,gill and visceral mass,were analyzed by GC-MS to clarify its lipid content and to estimate the possible main lipid storage site.The major fatty acid in all samples were,C16:0 and C18:0 as saturated fatty acids(SFA);C16:1(n-7),C18:1(n-7)and C18:1(n-9)as monounsaturated fatty acids(MUFA);and C20:4(n-6)(arachidonic acid: AA),C20:5(n-3)(eicosapentaenoic-EPA),and C22:6(n-3)(docosahexaenoic-DHA)as polyunsaturated fatty acids(PUFA).Relative percentage of lipid content of the mantle and visceral mass were 40.75%and 42.03%,significantly higher than 14.48%of adductor muscle and 17.15%of gill.Experimentally measured that adductor muscle had 16 types of fatty acid,mantle and gill had 18 types of fatty acid,and however visceral mass had 21 types of fatty acid,which types of fatty acid was overall than the other three tissues.Similarly,total fatty acids,SFA,MUFA of visceral mass were significantly higher than the other three tissues,PUFA were also significantly higher than the adductor muscle and the mantle.And the lipid and fatty acid composition of different shell length specifications and condition index were showed no significant differences.These results suggest that the visceral mass is the major site for Pinctada fucata to store lipid.And when performed fatty acid analysis such as food sources stadies of Pinctada fucata,there are no significant effect in different shell length and condition index.And its high content of PUFA such as DHA and EPA will have great research and application prospects.