Aim: To establish an HPLC method for the determination of 3-methyl-7, 8-dihydroxy-isochroman-4-one in the peel of Musa sapientum. Methods: A column of Shimadzu ODS-C_(18) column (250 mm × 4. 6 mm,5 μm), and a mobile phase of acetonitrile-water-phosphoric acid(9:91:0. 1) were adopted. A detect wavelength of 283 nm, a flow rate of 1 mL/min, and a column temperature of 35 ℃ were set. Results: The content of 3-methyl-7,8-dihydroxy-isochroman-4-one in the peel of Musa sapientum was 0.029 5%-0.036 7%. Calibration curve was linear over the range 1. 09-13. 08 μg. The average recovery was 100. 0%. The assay variability value was 0. 64 %(n=9). Conclusion: The method can be used for the quality control of Musa sapientum.