Developing　speed　correction　factors　(SCF)　are　important　for　the　evaluation　of　the　effect　of　speed　variations　on　vehicle　emissions.　However,　the　existing　methods　is　time　consuming　and　costly,　and　the　developed　SCF　are　in　low　resolution.　In　order　to　develop　the　SCF　in　high　resolution,　this　study　develops　a　method　for　deriving　SCF　for　Light-duty　vehicles　in　Beijing　based　on　vehicle　trajectory　data.　Massive　60＇s　speed-specific　trajectories　is　divided　from　the　vehicle　activity　data　and　grouped　into　speed-specific　trajectory　pools,　and　each　trajectory　pool　is　defined　by　the　average　speed　with　an　equal　interval　of　2　km/h.　Then,　the　vehicle-specific　power　(VSP)　distribution　is　established　for　different　speed　and　road　types.　Further,　based　on　the　emission　rates　and　VSP　distributions,　the　SCF　for　the　pollutants　are　derived　for　different　road　types　and　emission　standards.　The　analysis　result　shows　that,　the　proposed　method　can　generate　SCF　in　higher　resolution　compared　with　the　traditional　methods,　and　it　can　capture　more　accurate　traffic　characteristics.　Copyright　©　2017　by　Science　Press.