Abstract: There are GB method (the PRC standard), direct cooling method, melting method and solidification point method employed to determine the solidification point of modified crude oil. The solidification point of crude oil is mainly related to its chemical compositions and heating methods. Experiments showed that the different solidification point of crude oil can be obtained with different determining methods. According to the wax crystal structure of crude oil, the appropriate methods should be selected to determine the solidification points of different crudes. The paper points out that the melting method is suitable for determining the solidification point of the oil with relatively complex crystal textures such as Xingjiang and Changqing oil, and the direct cooling method and solidification method should be employed to determine the solidification point of the modified crude oil at laboratory. It suggested that a method to determine the solidification point of crude oil during operating should be established as soon as possible.