Synthetic plastics include polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polyurethane (PUR), etc. Because of their large molecular weights, high hydrophobic characters and high chemical bond energies, they are difficult to be degraded by microbes. More and more plastic products are widespread consumed and gradually accumulated in the environment, so that the “white pollution” has become a global concern. Therefore, safe and economic microbial degradation of synthetic plastics is an option. This article reviews microbial degradation of six petroleum-based plastics, including polyethylene, polystyrene, polypropylene, polyurethane, polyethylene terephthalate and polyvinyl chloride, from the aspects of microbial strains involved and the related enzymatic studies. This paper provides clues for the further study of the microbial degradation of synthetic plastics, including the screening of a variety of plastic degrading bacteria and microflora, and the functional identification of their degradation mechanism at the genetic, molecular and biochemical levels. Hopefully, efficient resolutions for complete biodegradation of plastics together with production of high added-value products can then be materialized in the future.