Abstract: A water-soluble MPA-CdSe quantum dots (QDs) was synthesized using mercaptopropionic acid (MPA) as a stabilizer. The structure, dispersion and morphology of the product were characterized by UV-vis spectra, fluorescence spectra, transmission electron microscopy (TEM) and XRD, respectively. The results showed that the target MPA-CdSe QDs had good dispersion (nano-sized ca.2~3 nm) and excellent fluorescence property,and the quantum yield reached 83% when reaction temperature and reaction time were 110  ℃ and 5 h, respectively.