OBJECTIVE To establish a HPLC method for the simultaneous determination of two main catechins (EGCG and ECG) and caffeine (CAF) which is a content limited substance in tea polyphenols. METHODS The separation was performed on a C₁₈ column (Agilent ZORBAX SB-C₁₈，4.6 mm×250 mm，5 μm) with the mobile phase consisting of acetonitrile（A）-0.05% phosphoric acid aqueous solution（B）by gradient elution. The gradient condition was as follows： 0-18 min，A：12%；18-20 min，A：12%-16%；20-35 min，A：16%. The flow rate was 1 mL·min-1. The column temperature was set at 30 ℃，and the UV detection wavelength was 278 nm. RESULTS The linear ranges and correlation coefficients of EGCG、ECG and CAF in tea polyphenols were 159.4-797.0 mg·L-1 (r=0.999 6)，40.16-120.18 mg·L-1 (r=0.999 7) and 1.6-12.8 mg·L-1(r=0.999 9) respectively. The limits of quantitation were 0.8，0.8 and 1.0 ng respectively. The limits of detection were 0.25，0.25 and 0.30 ng respectively. The average recoveries were 98.94%，99.45% and 100.46% with corresponding RSDs of 0.72%，1.00% and 0.83%，respectively. The RSDs were smaller than 2.0%. CONCLUSION The method is simple，accurate，reproducibility and can be used to determine EGCG，ECG and CAF in tea polyphenols.