Abstract：Diesel engine using lean-burn technology is arisen due to the big push driving from energy saving and exhaust reduction policy. The researches on the main diesel emission (PM and NOx) for fuel properties, new engine technologies, and after-treatment technologies are reviewed. As for air handing, the pressure ratio, layout of turbocharger and assembled turbochargers as well as the effect of combustion parameters on the new conception combustion and emission are described. The variable geometry turbocharger, the two-stage turbocharger, and electric turbocharger are the main technologies to content with the more stringent emission regulations. The combustion parameters are compress ratio, the EGR ratio, and the diameter of injector, etc. In order to improve the new combustion, it is necessary to develop the combustion model and simulation by using CFD. At the same time, the impact of injection strategies on emission reduction and the difference of low and high pressure EGR are presented. The main injection strategies include the multiple injection of the common rail injection system. Moreover, it is essential to improve the injection ratio and increase the injection pressure up to a high lever. It is a main technology to reduce the in-cylinder NOx emission. Compared with the high level EGR ratio, the medium level is the better solution for in-cylinder pollution control. NOx control is centered on Selective Catalytic Reduction (SCR) and NOx Storage Reduction (NSR) for diverse applications. The focus is on the V/W/Ti and zeolite catalysts for SCR technology. As for NSR technology, a typical NSR catalyst formulation contains basic NOx storage components (mostly barium species), Noble Metals (NM), such as Pt, Rh, Pd, and support oxides. Diesel Particulate Filter (DPF) technology is very effective for the PM control. Improved DPF substrate and new DPF regeneration strategies are described. Finally an update on Diesel Oxidation Catalysts (DOC) is provided to show the potential solutions for HC and CO emissions.