The extraction of the fatty acids from viscera gland of Chlamys farreri and Pecten yesoensis cultured off shore Dalian was studied and the fatty acids in fat were analysis.The results show that extraction rate,3.01%,is the highest when gas(CO 2) is filled up to expel oxygen,the ratio of material to water is 1∶2,the time is 60 minuites and temperature is 100℃.The contents of the unsaturated fatty acids of viscera gland fatty acids in Chlamys farreri and Pecten yesoensis are 32.0% and 32.8% respectively,in which the contents of EPT+DHA are 13.6% and 13.8% respectively.