Thioglycolic acid capped CdTe quantum dots (QDs) was prepared via hydrothermal synthesis method. Based on the synchronous fluorescence enhancement of CdTe QDs in the presence of streptomycin, a synchronous fluorescence method for the determination of streptomycin residue was established. Influence factors including pH value of buffer solution, concentration of CdTe QDs and reaction time were investigated. The samples were extracted with methanol by ultrasonic processing, and were added into the solution which was composed of 1.0 mL of CdTe quantum dots (3.5×10^-5 mol/L) and 1.0 mL of Tris—HCl buffer solution (pH=6.0). After standing for 10 min, the synchronous fluorescence intensity were measured at 345 nm (Δλ=230 nm). The relative synchronous fluorescence intensity showed good lined relationship to streptomycin concentration in the range of 5.0×10^-7～1.0×10^-5 mol/L with the correlation coefficient of 0.999 7. The detection limit was 1.0×10^-8 mol/L. With the advantages of simple, rapid and high sensitivity, the proposed method can be used in the determination of streptomycin residue in tomatoes samples.