To establish an HPLC method for the detection of optical isomer in selegiline hydrochloride, the chromatog. conditions including column, mobile phase and detection wavelength were optimized.The linearity, precision, recovery, detectability and stability of sample solution were investigated.The results indicated that under the optimized conditions (cyclohexane and isopropanol (99.8:0.2) as mobile phase, flow rate 1 mL/min-1 and temperature 10-30°), R and S-selegiline hydrochloride could be separated effectively.The proposed method could be applied to detect the dextroisomer in selegiline hydrochloride.