The technique of SPME-GC/MS has been established. The authors made a comparative analysis of the SPME-GC/MS technique and headspace in Nanyang Depression of Henan Province, and the results show that oil-gas implications of headspace-methane and SPME indicators are accordant with each other. The results of surface water and oilfield water in Sichuan Basin show that oil and gas properties of the drill hole can be more accurately determined by the SPME-GC/MS spectral features of oilfield water.