Abstract: A random polyether was synthesized from ethylene oxide(EO) and propylene oxide(PO) using(1,2-)propanediol as initiator,and the influences of chain structure on the properties of the polyether were discussed.Nylon 66 spinning finish was prepared with the polyether and its spinnability was tested.The results show that the spinning finish made from RP04 and RP09 has excellent gliding property,thermal stability and wettability,and can satisfy the requirements of nylon 66 spinning finish.