This paper describes the progress of the research and practice on incorporating mobile sources, especially motor vehicles, into Shenzhen Emissions Trading System. Insights gained through Shenzhen's experience will provide useful insights to others that may have cause to consider the expansion of their Emissions Trading System (ETS) to include mobile sources. In order to incorporate public transportation into the ETS pilot, the city has formulated quantitative greenhouse gas emissions standards for bus and taxi companies, drawn the baselines for energy consumption and carbon emissions of public transportation, and revised local emissions trading regulations. For the further inclusion of non-public transportation vehicles, studies were made on emissions quantification, allowances allocation, non-compliance penalties, and emission reductions certification. In the future, the work will focus on legal safeguards and trading mechanisms.