Abstract: The current oil fingerprint identification technology is mainly based on the chemical composition and distribution characteristics of spilled oil to identify the type and source of spilled oil. In this paper, the carbon stable isotope ratio (δ¹³C) of the total components of the samples collected from different oil products, under different weathering degrees and contaminated with different environmental media were determined, and the difference of the determination results of the samples with spatiotemporal correlation were analyzed, which provides a new traceability technical method for the identification of oil spills, and provides diversified evidence support for the maritime authorities to carry out the investigation and treatment of marine oil spill pollution accidents from ships. Four kinds of oil spill weathering experimental samples, source term samples and field pollution samples from the oil spill accident of the "Sangji" ship in the East China Sea, the fuel oil spill accident of the "Zhengli Los Angeles" ship in Jiangyin port of Fuqing, Fujian Province, and the fuel oil spill accident of the "Xinhaisheng 168" ship in Kanao anchorage of Pingtan, Fujian Province were analyzed for total component δ¹³C and the traceability technology based on difference analysis were studied. The results show that δ¹³C of different oil weathering samples has a similar trend with the increase of weathering time, which can be used to explain the homologous correlation of corresponding oil types. The δ¹³C difference of cargo oil and fuel oil in oil spill accident ship can be used to identify the types of oil spill samples collected in the accident sea area. The oil spill samples collected from fuel tanks of the incident ship and from the oil spill cleanup site can be used to trace and compare the δ¹³C differences between the oil samples collected from the contaminated environment. Under normal environmental conditions, the difference limit of high homology similarity is twice of the analysis error of parallel samples.