Gardeniae Fructus (Gardenia jasmmoides Ellis) is widely used as a natural food colorant and as a traditional medicine for the treatment of hepatic and inflammatory diseases. The quality evaluation of Gardeniae Fructus was carried out by HPLC using geniposide as a marker. The geniposide was isolated from commercial Gardeniae Fructus on ODS column using a mixed solvent of acetonitrile-water (v/v 9:91) as mobile phase and a detection wavelength 240 mm. The content of geniposides in twenty different samples was in a range of 1.20% to 7.17% of total tissues and the average was 4.97%.