Highly fluorescent and stable ZnSe quantum dots were synthesized by afacile colloid aqueous phase route. It overcame the defects such as instabilityand low quantum yields of the quantum dots synthesized by early aqueous phaseroute. Optimum conditions were found. L-glutathione was used as the stabilizer,the molar ratio of L-glutathione, Se2- and Zn2+ is 5∶1∶5, the reaction media ispH 10.5, and the proper temperature is between 90 and 100 ℃. Quantum yields(QYs) could reach to 50.1% without post irradiation in prime syntheticalconditions. And the fluorescence intensity of ZnSe QDs almost didn’t changeafter 3 months. Its water-soluble property is also excellent. The properties ofZnSe QDs were characterized by means of ultraviolet visible spectra, fluorescencespectra, and transmission electron microscopy. The synthesized ZnSe QDs emitblue-purple fluorescence (370 nm) when excited at 300 nm. And the excellentphotochemical characteristics of the ZnSe QDs will be advantageous in theapplication in optothermal device manufacture and chemistry biology domain.