Abstract：Tightening emission standards for heavy-duty in use diesel required a new effective diesel emission control system. Since 1989, Diesel Oxidation Catalysts (DOCs) have been adopted by Diesel passenger vehicles in Europe and a number of studies on the use of such catalysts to meet current legislation limits have been published. The primary purposes are oxidation of CO, unburned hydrocarbons, and NO, while active hydrocarbon oxidation could be also used to generate exotherms required for downstream components. The main advances for catalysts in the last decade are systematically reviewed. Special attentions are given to the structure of DOCs, fundamental reaction, and the DOCs catalysts deactivation and regeneration. DOCs consist of case package, monolith, damping layer, and catalysts. The precious metal component of the catalyst is typically regarded as the active site for the reaction. The most common precious metals used for DOCs are Pt and Pd. Catalyst deactivation is becoming a constant concern for catalytic converters, because it is a natural phenomenon caused by several methods, including sintering of active sites, poisoning by sulfurous compounds, and washcoat covered by carbon oxidation products. At last, the development tendency for DOC technology is proposed.