The　traffic　flow　at　signal　intersection　shows　different　characteristics　due　to　the　influence　of　adverse　weather.　Setting　specific　signal　control　scheme　in　adverse　weather　conditions　is　an　important　way　to　reduce　its　negative　influence　on　the　traffic.　The　signal　intersections　of　different　types　and　scales　in　Beijing　are　selected　as　the　investigation　spots　in　this　study.　Based　on　the　weather　data　and　traffic　flow　data　obtained　from　video　detectors　through　the　months　of　April　2012　and　February　2013,　the　characteristics　of　indicators　including　saturation　headway,　saturation　flow　rate　and　start-up　lost　time　in　different　intensities　of　adverse　weather　are　analyzed.　The　relationship　models　between　the　indicators　and　the　precipitation　are　established　by　significance　testing　and　regression　modeling.　Consequently,　the　influence　of　the　rain　and　snow　on　the　traffic　flow　of　intersections　is　described　quantitatively.　Finally,　the　adverse　weather　is　classified　into　four　grades　based　on　its　influence　degree　on　the　intersection　traffic.　These　traffic　flow　characteristics　in　every　grade　of　adverse　weather　provide　applicable　parameters　for　the　optimization　of　traffic　control　scheme.　©,　2015　All　right　reserved.