Cu2+-doped ZnSe quantum dots (ZnSe:Cu2+ QDs) are synthesized in aqueous solution via a co-precipitation method with thioglycolic acid (TGA) as a stabilizer. Green emission is observed under 365 nm UV excitation. X-ray diffraction patterns and transmission electron microscopy image show that ZnSe:Cu2+ QDs are sphalerite cubic structure, similar to round in shape, the average diameter is 6 nm. The concentration of Cu2+ ions and TGA, pH, reaction time and aging time have influences on optical properties of ZnSe:Cu2+ QDs. The luminescence of as-prepared products with different parameters is characterized using fluorescence spectrophotometer. The high fluorescence intensity has been got when the concentration of Cu2+ ions is 4.0% (molar ratio), TGA is 83.4 μl (mol ratio Zn: TGA=1:2), pH is 9.5, reaction time is 2h. The luminous intensity increases with the extension of aging time.