Objective An HPLC method was established for simultaneous determination of the contents of four components in Phyllanthus Emblica, and the changes of the contents of the four components under different pH conditions were studied. Methods The contents of PA, GA, TGG and β-PGG in Phyllanthus Emblica were determined by HPLC. The column was an Agilent Zorbax C18 bonded silica column (150 mm × 4.6 mm, 5 μm). The mobile phase was methanol -0.1% phosphoric acid gradient and the flow rate was 1.0 mL/min. The detection wavelength was 280 nm at 25℃, the injection volume was 10 μL. Then the contents of four components under different pH conditions were determined. Results PA, GA, TGG, and β-PGG range from are 0.0229-0.2290 mg/mL (r=0.9996, n=6), 0.0148-0.1480 mg/mL (r=0.9991, n=6), 0.0018-0.0180 mg/mL (r=0.9998, n=6), 0.0031-0.0310 mg/mL (r=0.9993, n=6) respectively, showed a good linear relationship, and the recovery rates of the samples all met the requirements for content determination. The content of PA in Phyllanthus emblica was highest at pH 2, GA was highest at pH 5, TGG was highest at pH 4, β-PGG was highest at pH 3. Conclusion This method is simple and accurate, and can be used to determine the content of PA, GA, TGG and β-PGG in Phyllanthus Emblica. By studying the content changes of PA, GA, TGG and β-PGG in Phyllanthus Emblica under different pH conditions, it can provide a certain theoretical reference for the quality control of related ingredients in Phyllanthus Emblica.