Abstract: Entrapped hydrocarbons from asphaltene and products from the ruthenium ions catalyzed oxidation (RICO) of asphaltene were used to study the biodegraded crude oil. The results indicate that the biomarkers, which are almost destroyed by biodegradation in the oil, can be recoveried from asphaltene by these two methods. A fairly intergrate series of hopanes and steranes are discovered in the entrapped hydrocarbons, and a homologous series of hopanoic and steranoic acids are also detected in the RICO products. Compared with other methods, these methods are simple and convenient, and the results obtained are credible and accurate. Hence, these new methods are significant for the study of biodegraded crude oil.