Objective:To establish a HPLC method with precolumn dervatization of γ aminobutyric acid (GABA) in nowfoodking capsules.Methods:GABA was determined on Hypersil ODS column(125mm×4.0mm,5μm) using gradient elution with mobile phase of A[20mmol·L -1 NaAc (pH7.2)+ 0.02%triethylamine(TEA)(pH 7.3 )]and B [100mmol·L -1 NaAc(pH 7.3 ) acetonitrile ethanol(100∶175∶225)].The detective wavelength was 338nm.Results:The linear range was 0.05~ 1.03 mg· mL -1 with equation of A =423 784 C +6...