In order to develop a method for the determination of mirabelone API content, high performance liquid chromatography (HPLC) was used. The chromatographic column was GLInertsil ODS-3 C-18 column (4.6×250 mm, 5μm). Mobile phase: using a buffer solution (0.1% phosphoric acid solution, pH vaule adjusted to 6.0 with triethylamine)∶ methanol = 65∶35 (V/V); flow rate: 1.0 mL/min; detection wavelength: 210 nm; injection volume: 10 μL; column temperature: 30 ℃. The results show that the test sample concentration of milaberone in the range of 0.25 to 0.75 mg/mL presents good linear relationship, the linear equation was y = 725.53x-2.178 (r2=0.999 7); the detection limit was 0.167 μg/mL, the quantitative limit was 0.624 μg/mL; the RSD of the 48 h solution stability test is 0.27%; the RSD of the repeatability test is 0.15% (n= 6); the RSD of the intermediate precision test is 0.12% (n=12); the average recovery rate is 99.61% (RSD of 0.79%); the content of three batches of raw drug samples determined by this method is within the range of 98.0% to 102.0%. The results show that the data obtained by this method are stable, reliable, reproducible and stable, and the chromatographic conditions are durable, which can be used to determine the content of Mirabelone.