Abstract: Well Shacan No. 2, located in the Yakela-Luntai structural zone of the Tabei (Northern Tarim Basin) uplift, is 46 km away from well Lunnan No. 1, which is located in the southern slope of the uplift. Through the analysis of oiomarkers in saturated hydrocarbons and pyrolytic products of asphaltenes of oils from the two well, the author found that the oil from well Shacan No. 2 has the same source as the oil from well Lunnan No. 1 , and that the former has undergone a secondary migration of longer range than the latter. The oils were biodegraded in the geological history and therea fter accumulated once again.