Abstract: A systematic determination method for 10 drugs of abuse, morphine,codeine, 6-monoacetylmorphine, heroin, levorphanol, pethidine, ethylmorphine, anadol, pentazocine and ethamivan, using high performance liquid chromatography is described. Separation of the 10 drugs was achieved on a 25 cm×4.6 mm ID, 10 μm Zorbax C8 column, using methanol —0.05 mol·L^-1 KH₂PO₄— diethyl amine (27∶73∶0.5, pH 4) as mobile phase. Codeine was used as the interal standard. Calibration graphs were linear over the concentration range of 10～200 μg·ml^-1 and regression equations showed correlation coefficients of greater than 0.999. Precision (RSD) were found to be better than 3% for each compound. Precision and linearity of the method are satisfactory for clinical toxicological applications. The extraction procedure yielded cleaner extracts. The recovery rates from urine were all above 87% without interference. This method is rapid, sensitive and specific.