Glutathione (GSH) capped CdTe quantum dots (GSH-CdTe QDs) were synthesized in aqueous solution. The mechanism of interaction between GSH-CdTe QDs and L-Aspartic acid (L-Asp) was studied by UV-vis absorption，resonance Rayleigh scattering (RRS), fluorescence and infrared spectra. In pH 5.3 BR buffer solution, L-Asp could be combined with the GSH-CdTe QDs by the electrostatic attraction and hydrogen bond, forming a bigger diameter aggregate, which resulted in RRS increased markedly and the fluorescence of GSH-CdTe QDs quenched sharply. The increased RRS intensity and the quenched fluorescence intensity were directly proportional to the concentration of L-Asp in a certain range and the sensitivity of RRS method was higher (the detection limit for L-Asp was 14.2 ng•mL^–1) than the fluorescence method, so a new sensitive RRS method for the determination of L-Asp was established by using GSH-CdTe QDs as a probe. In addition, the optimum conditions of the reaction and the influences of coexisting substances were tested by RRS method, which could be satisfactorily applied to the determination of L-Asp residues in urine samples.