Abstract: Sudanese crude oil is a kind of highly waxy and vis- cosity crude oil.The effectiveness of pour depressing de- pends on the constituent of crude oil,such as wax concen- tration,carbon amount distribution and composition,res- in and asphaltene.To assure the safety operation of Su- danese Blended Crude Pipeline,based on the properties of crude oil in Sudanese 3/7 blocks,a gel point depressant having a good modifying effect for Sudanese Pipelining crude oil is selected.The test results shows that adding 0.1 wt% of SL2 depressor could reduce gel point from 40℃to 30℃and get 30% reduction of apparent viscosity of Sudanese crude oil at 50℃,and effectively improve the flow behavior of the crude oil under low temperature.