Recent research has shown that aerosol particles in the stratosphere cannot be formed through homogeneous nucleation process. However, this conclusion is obtained by assuming the ambient temperature to be -50¿C or -55¿C, but in reality it is not unusual that in certain regions of the stratosphere temperature can be as low as -75¿C or even lower. To assess the influence of temperature on the formation of sulfate aerosols in the stratosphere, and to explore the possibility of forming new particles through homogeneous nucleation processes at certain regions where the temperature is extremely low, the classical nucleation theory is applied to calculate the temperature dependence of the characteristics and nucleation rates of sulfate aerosols in the binary H2SO4-H2O vapor mixture. Our calculated results indicate that the number of new particles formed at a lower temperature is orders-of-magnitude larger than that at a higher temperature when the concentration of water and sulfuric acid vapors are kept constant. At stratospheric regions with low temperature there may exist large amounts of ultrafine particles that can hardly be detected by conventional methods.