Objective To determine the content of taurine in Mactra veneriformis by pre-column derivation HPLC.Methods Ultrasound method was used for the extraction of taurine from Mactra veneriformis.In alkaline condition,amino acids reacted with phenyl isothiocyanate and resulted in the derivatives of benzene isothiocyanate-amino acid complex.Kromasil C18 column(4.6 mm ?250 mm,5 ?m) was used and the absorbance at 254 nm was measured.The mobile phase consisted of sodium acetate solution,water and methanol.Results Corresponding chromatographic peaks of taurine were obtained in extract sample and the control.The linear range of taurine was from 10.04 ?g?mL-1 to 50.20 ?g?mL-1,and the recovery was 97.95 %(RSD=1.41%,n=9).Conclusion This method is simple,accurate and reproducible.The seasonal variation range of taurine level is from 10.56 mg/g to 20.91 mg/g,and the taurine level arrived to the peak in June.