The water soluble CdTe quantum dots (QDs) with different surface charge and the same size were synthesized in aqueous solution. The negatively charged gold nanoparticles (AuNPs) were also prepared by the citrate reduction method. The quenching activity of AuNPs on the fluorescence of these QDs was investigated. The results indicate that the negatively charged AuNPs have stronger quenching capacity on fluorescence of the positively charged CdTe QDs.Efficiency of AuNPs quenching on the fluorescence of positively charged CdTe QDs and negatively charged CdTe QDs is 0.640~0.846 and 0.534~0.690 respectively at different pH values. So, the electrostatic attraction between AuNPs and CdTe QDs can enhance the quenching activity of AuNPs.