Two hydrocarbon-degradating bacteria were isolated from petroleum contaminated soils and identified. These two strains are all Pseudomonas sp. and designated as ptr13 and ptr20. Their aromatic hydrocarbon degradation ratios were 80% and 69%, respectively. GC-MS assays showed that the light components of the crude oil were disappeared after degradation, and at the same time, the “unresolved complex material (UCM)” emerged. Enzyme assays indicated that ptr13 and ptr20 present significant catechol 2, 3-dioxygenase activity.