The present study established a method to determine 7 hydroxy metabolites of polychlorinated biphenyls (PCBs) in aquatic products.Target compunds were extracted by hexane/ethyl acetate (v/v,1:1). Sulfuric acid and silica column were used to remove the impurities with 50 ml of hexane/ethyl acetate (v/v,1:1) as eluet. Silylation derivatization was effective and stable to make hydroxylated polychlorinated biphenyls more volitile for GC/MS analysis. The coefficients of derivivatives ranged from 0.996 to 0.999 in the range of 1-100 ng/g. Recoveries of spiked tissues prepared with this method ranged from 76.7% to 106%,and the relative standard deviations (RSD) ranged from 4.0% to 11.1%. The method was applied to determine hydroxy-PCBs in aquatic products sampled from local market.