Abstract: Biological technology especially microbial enhanced oil recovery technology attracts the tremendous attention of the petroleum engineers.The paper briefly presents the development overview of microbial enhanced oil recovery (MEOR)technology,introduces emulsity-carry,strip of oil film,biogas and its concentrate on local interface, describes micro-organism selection and criterion of praise and points that MEOR can improve the recovery ratio ef- fectively.The application proves that the technology has better development prospects.