A novel method for the detection of streptomycin（SM） residue in cucumber was developed based on the enhancement of the fluorescence intensity of CdTe quantum dots（QDs） in the presence of SM.The factors that influence the detection of SM were investigated,and the optimum conditions were investigated.Under the optimum conditions,a good linear relationship was found between relative fluorescence intensity of the system and concentration of streptomycin in the range of 5.0×10-12-1.0×10-10 mol/L with a correlation coefficient（r） of 0.999 0.The detection limit was 5.0×10-13 mol/L,and the recoveries were between 99% and 106%.With the advantages of high selectivity,low detection limit,simpleness and speediness,the proposed method was successfully applied in the detection of trace streptomycin residue in cucumber.