Abstract: The wax deposition of Xinjiang crude oil in pipeflow was studied. The authors researched the effect of crude oil composition, oil temperature, difference between oil and pipe wall temperature on wax deposition on pipe wall, analyzed parameters of the wax deposit including wax appearance temperature, average latent heat of wax crystallization by Differential Scanning Calorimeter (DSC), and also discussed the wax precipation and deposition of Xinjiang crude oil from microscopic mechanism.