Abstract: This paper hriefly introduces the progressive general situation of pour point depressant in the world. pressanl are mainly discussed, including the effect of the contents of paraffin; the temperature and quantity of pour point depressants; cooling velocity and shearing rate. The kinds of depressants and application in the oil field are listed. The current study fields are as following: the mechanism of depressants; the better depressants for Daqing crude oil and the influnce between different chemicals used in crude oil.