Advances in the screening of polycyclic aromatic hydrocarbons (PAHs) degrading strains, their biodegradation mechanisms and the PAHs bioremediation are introduced. Recently isolated PAHs degrading microorganisms include Bacillus , Mycobacterium , Nocardia , Sphingomonas , Alcaligenes , Pseudomonas and Flavobacterium. The biodegradation pathways for naphthalene and phenanthrene have been well reported while it is under active study for structure complex PAHs. Environmental factors affecting PAHs biodegradation include bioavailability enhanced by surfactants and cometabolism and augmentation caused by multiple - substrate existence. PAHs bioremediation in soil is considered as an effective approach to solve the most difficult environmental problem caused by organic contamination.