Abstract: The concentrations of petroleum hydrocarbons (PHs) from the surface and core sediments, which collected from oil and gas exploration area in central Bohai Sea, were analyzed, and their environmental quality was evaluated. The results showed that the PHs contents in surface sediments ranged from 10.15106 to 151.72106, with an average of 55.99106 in the study area. Most stations are medium pollution, some stations appear higher and severe pollution. High PHs value areas locate in the Bohai Bay coast, indicating that PHs contamination is significantly affected by coastal human sewage and oil and gas extraction. Before the 1930s, the PHs concentrations were in a low background value, following by an increasing trend resulting from the impact of human activities. The PHs evolution in the area agrees with the development periods of oil and gas exploration in the Bohai Sea. The oil spill event of the Platform Penglai 19-3 in June 2011 has affected the adjcent sediments obviously, but the impact has significantly reduced after 1 year.