Abstract: A method to detect the content in the freeze-drying preparation of cisplatin was established. The method uses normal-phase high performance liquid chromatography and N,N-dimethylformamide as solvent, the mobile phase include ethyl acetate, methanol, N,N-dimethylformamide and water (the proportion of mixture is 25∶16∶5∶5,V/V/V/V).The flow rate is 1.5 mL/min, injection 20 μL and UV-310 nm as detector. This method has a good linear correlation .The recovery rate is 99.6%~100.3% and detection limit is 59.2 mg/L, the degree of accuracy is 0.21%(n=6).