The contents of gallic acid in geranium from different areas were determined by HPLC method, the content differences of gallic acid between them were compared with the mobile phase of acetonitrile-0.1mol/L phosphoric acid solution(2∶98), a flow rate of 1.0 mL/min and the detection wavelength of 272 nm. Results show that the standard solution of gallic acid show a good linear relationship at the range of 10 ~ 120μg/mL, the regression equations of the relationship between concentration and peak area was A=19.112c－125.47, r2= 0.999 7, and the average recovery was 101.33%， RSD was 1.04%. The method used to determine the content of gallic acid in geranium is simple, rapid and accurate.