Abstract: The characteristic temperatures of crude oil mean the special temperatures, such as wax appearance point and pour point and so on, corresponding to the abrupt change of the rheological properties of the oil. In the light of super-cooling and the super-heating problem of wax crystallization and melting during the continuous cooling and heating process, it is impossible to exactly determine the characteristic temperatures such as wax appearance point only depending on the shear stress and temperature curves for one of the processes. At the same time, it is difficult to exactly measure the wax appearance point or cloud point of crude oil by means of eye-measurement method because of oil always is fuscous. Therefore, a method of mean viscosity and temperature curve for continuous heating and cooling process is presented. To a wider extent of measuring temperature, this method can measure not only wax appearance point but also abnormal point and pour point. The conventional methods confirms its reliability.