Abstract: A reliable analytical method based on volumetry was developed for the determination of acid value in aquatic products. Samples were extracted with mixed solvent including diethylether and ethanol; then they were titrated with potassium hydroxide. The titration end point was indicated by dihydroxyphthalophenone. The recovery was calculated based on potassium hydroxide consumed in titration. The average recoveries at the levels of 0.100 g and 0.200 g were 94.3% and 96.1%;RSDs were 3.53% and 4.01% (n=6), respectively.