The ratio spectrumderivative spectrophotometry was used for the simultaneous determination of sodium salicylate,coffeine and phenazone in the Satongfeng Injection.The mean recoveries of sodium salicylate,coffeine and phenazone in synthetic samples were 99.7%,101.4% and 99.3% respectively. The relative standard deviations (RSD) were 1.7%,1.8% and 1.2%(n=5). The results of this method were compared with those of the standard method by the t test, showing no significant difference(t 95,8 ). The ratio spectrum derived spectrophotometry was used for the simultaneous determination of sodium salicylate, coffeine and phenazone in the Satongfeng Injection. The mean recoveries of sodium salicylate, coffeine and phenazone in synthetic samples were 99.7%, 101.4% and 99.3% respectively. (RSD) were 1.7%, 1.8% and 1.2% (n = 5). The results of this method were compared with those of the standard method by the t test, showing no significant difference (t 95,8).