On the basis of unique structural characteristics of α-cyclodextrin,α-cyclodextrin modified CdSe/CdS nanoparticles have been successfully synthesized in aqueous media.Techniques of AFM,TEM,EDS,FTIR,UV-vis absorbance and photoluminescence spectra were used to characterize the morphology,composition and optical characteristics of the synthesized nanoparticles.The results showed that the as-synthesized nanoparticles were elliptical and composed of several small particles.Their average length and diameter were about 20 nm and 15 nm.CdSe/CdS nanoparticles had single well-crystallized hexagonal structure.Packaged with a shell of CdS on the surface,α-CD/CdSe-CdS nanoparticles exhibited a red shift in the absorption spectrum,intensity growth in the emission spectrum and a substantial increase in Quantum yields.The size distribution could be adjusted by precursor ratios in the presence of α-cyclodextrins.