A fluorescence probe,2-Hp-β-CDCdTe QDs for the detection of crystal violet(CV) was fabricated in the presence of TGA as stabilizer and 2-hydroxypropyl-β-cyclodextrin(2-Hp-β-CD) as modifier,which showed high fluorescence intensity,water solubility and light stability,as well as good inclusion ability for CV.The interaction between 2-Hp-β-CDCdTe QDs and CV was investigated by UV-Vis,fluorescence spectroscopy and TEM.The data indicated that the distance between the donor and the acceptor was reduced significantly by the action of CTAB,and the energy transfer between the QDs and CV was promoted.The fluorescence spectrum for QDs could overlap the absorption spectrum of CV effectively.Based on this,the fluorescence resonance energy transfer(FRET) system between QDs and CV was established,which could be used for the determination of CV.Results showed that in pH 8.0 Tris-HCl buffer,CV could quench the fluorescence peak of 2-Hp-β-CDCdTe QDs in the presence of CTAB,and there was a good linear relationship between the change of fluorescence intensity(ΔF) and CV concentration in the range of 1.0×10-7-1.0×10-5 mol/L(r2=0995 2).The detection limit was 1.74×10-8 mol/L,and the average recoveries were in the range of 99.0%-106%.