Objective To establish a method to assay 3 active components in pharmacy compounded terbinafine ointment simultaneously. Methods High performance liquid chromatography (HPLC) equipped with the ZORBAX SB-C₈ (4.6 mm×250 mm, 5 μm) was used for the assay. The mobile phase was methanol-0.1% phosphoric acid (70∶30). The flow rate was 1.0 ml/min with the 248 nm detection wavelength, 10 μl injection volume and 30 ℃ column temperature. Results A good linear relationship was observed in the range of 20.4-204.0 µg/ml for terbinafine hydrochloride(r=0.999 7), 40.4-404.0 µg/ml for mupirocin(r=0.999 8), 2.02-20.20 µg/ml for mometasone furoate(r=0.999 7). The average recovery of each detected component in terbinafine ointment was 99.39%, 99.21%, 99.97% with the RSD 0.82%, 0.59%, 0.81%(n=9). Conclusion This method is simple, rapid and accurate. It can be used to detect the content of terbinafine, mupirocin and mometasone furoate in pharmacy compounded terbinafine ointment.