Abstract: To study the organic acids in wampee fruits, the constituent and content of organic acid in 12 wampee germplasms were analyzed by ultrasonic-assisted water extraction and high performance liquid chromatography (HPLC). The results show that six organic acids can be successfully separated and all the calibration curves for these organic acids display a good linear relationship with correlation coefficients of 0.9975-0.9996, RSD is 1.02%-1.84% (n=5) and recovery rate is 95.60%-101.78%, on the condition that Venusil XBP C18(T) column (4.6 mm×250 mm, 5 μm) is used at 27℃, mobile phase is 0.01 mol/L (NH4)₂HPO₄ (pH 2.6) with flow rate of 1 mL/min and detection wavelength of 210 nm. The major parts of organic acids in wampee fruits are citric acid, oxalix acid and malic acid, lactic acid is detected only in a few samples; in different samples, the content of citric acid, oxalic acid and malic acid is 0.780-8.090 mg/(g.FW), 0.773-4.205 mg/(g.FW), 0.478-3.212 mg/(g.FW), respectively, and accounts for 22%-65%, 16%-40% and 11%-20% of the total acid.