Abstract: To meet the need of design of Urumchi-Lanzhou Oil Pipeline.the evaluation experiment of depressant injection is made on Northern Xinjiang Crude and Tuha Crude. Based on the test of high-speed temperature-drop, simulation experiment on depressant injection under designed transportation condition and oil storage experiment are carried out, and the depressant applicable for Northern Xinjiang Crude and Tuha Crude, ideal heating temperature, depressant injection concentration and injection position are determined. The result demonstrates that both kinds of oil are feasible to be transported and stored at ambient temperature technically through one-position injection of depressant. Suggestions on applying a new concentration of depressant for both oils are put forward.and technical and economical analysis is made.