Sulphate-reducing bacterial (SRB) metabolites could reduce both surface and interfacial tensions between air/liquid and oil/liquid respectively, and also able to form a stable emulsion system with crude oil. Oil recovery rate of SRB from saturated oil sand was determined as 39.2%. Three fraction ratios (alkane, asphaltene and NSO) were significantly reduced after 3-month bio-degradation. Also, significant decreases of three n-alkanes (C11-C13) were determined. However, there was no remarkable change in composition of aromatics during 3-month experiment. Both SRB metabolite/oil emulsion and bio-degradation partially contributed to a reduction of oil viscosity. The amount of reduced SO4- was about 77.4 mg in 20 days by SRB using TPH as the unique carbon sources.