Under acidic conditions，the flourescence of CT2R could be enhanced with silver nanoparticles because of its surface enhancement effect.This enhancement effect would be decreased in the presence of BSA.The decreased fluorescence intensity is proportional to the concentration of BSA.According to this principle，a simple and new method for BSA determination was developed.The influences of some experimental factors，including pH value，concentration of CT2R，concentration of silver nanoparticles，addition order of reagents on the determination of BSA were investigated.Under the optimal conditions，the linear range for BSA detection is 0.02-1.00 mg/L，with a detection limit of 0.002 6 mg/L.The method was used in the detection of BSA in synthetic samples with satisfactory results.