Abstract: In this study, the community structure of aerobic methanotrophic communities were investigated at light hydrocarbon microseeps above a known oil band gas field in the Shengli Oilfield. Clone library analysis of the pmoA gene revealed major differences in the methanotrophic community composition between oil and gas fields and the surrounding soils. The relative abundance of methanotrophic Methylocystis and Methylosinus (type Ⅱ) in surrounding soils is obviously lower in oil and gas field soils than surrounding soils, ut the relative abundance of methanotrophic Methy-lococcus and Methylocaldum (type I) presents a reverse tread. Terminal restriction fragment length polymorphism (T-RFLP) analysis confirmed that one distinct Methylococcus and Methylobacter-related group may dominate the community at hydrocarbon microseeps. The pmoA gene copy numbers determined by real time PCR also indicated that methane oxidizing microbial community anomalies above typical oil and gas reservoirs exist objectively.