Indigenous aromatic hydrocarbons degraders (AHD) are the primary member for bioremediation of oil-contaminated soils. In the present study, the aromatic hydrocarbons degraders and catechol 2,3-dioxygenase (C23O) gene were determined. Abundant degradative bacteria were detected and a 934 bp DNA fragment of C23O was amplified in two of four heavily contaminated soils (oil content>10000 mg/kg), indicating a relationship between abundance of AHD or C23O copies and oil content. Sequences analysis of C23O gene implied a possible pseudomonad origin. This study suggested a possibility of monitoring bioremediation of oil-contaminated soils and screening degradative bacteria resources by determining the number of aromatic hydrocarbons and abundance or diversity of degradative genes in soil.