This work studied the effect of differential temperatures on the latent heat in the nucleation of CdSe quantum dots(QDs).The result showed that,by the formula of phase change,with increasing the reaction temperature,the latent heat in the nucleation of QDs reduced.CdSe QDs with the size-dispersion from 2.7 to 3.6 nm were synthesized via oleic acid-paraffin liquid system by controlling the reaction temperature from 180 to 220℃.Synthesized QDs were characterized by UV-vis absorption spectra and X-ray diffraction(XRD).The result of UV-vis absorption spectra showed that with increasing of reaction temperature,the first absorption peak was red-shifted and the size of QD increased.The result of XRD showed that the synthesized QDs were zinc-blende structure. The work studied the effect of differential temperatures on the latent heat in the nucleation of CdSe quantum dots (QDs). The result showed that, by the formula of phase change, with increasing the reaction temperature, the latent heat in the nucleation of QDs reduced .CdSe QDs with the size-dispersion from 2.7 to 3.6 nm were synthesized via oleic acid-paraffin liquid system by controlling the reaction temperature from 180 to 220 ° C. Synthesized QDs were characterized by UV-vis absorption spectra and X-ray diffraction (XRD ) The result of UV-vis absorption spectra showed that with increasing reaction temperature, the first absorption peak was red-shifted and the size of QD increased. The result of XRD showed that the synthesized QDs were zinc-blende structure.