Abstract: In a Tris-HCl buffer medium of pH 9.40,sensitization effect of cetylpyridine chloride monohydrate (CPC) on the fluorescence of amoxicillin was observed obviously.The magnitude of increase in fluorescence intensity was found to keep linear relationship with the mass concentration of amoxicillin in the range of 0.2-87.7 mg·L-1,when measured at the wavelengths of 274 nm (λem) and 304 nm (λex).Detection limit (3s/k) of the reaction was found to be 0.026 mg·L-1.The reaction was used as a method to determine amoxicillin and was applied to the analysis of amoxicillin injections and amoxicillin capsules.Results obtained were in conformity with the labelled values,and values of average recovery and RSD′s (n=6) found were 100.8% and 2.5% (for injection),and 97.8% and 3.2% (for capsule).