Aiming　at　the　process,　mode　and　characters　of　urban　road　traffic　safety　management,　four　databases　model　of　DSS　integrating　decision　support　system　theory　and　technology　was　adopted　to　collect,　analyze,　manage,　decide　and　feed　back　road　traffic　safety　information.　The　system　function　and　structure　were　studied　according　to　the　general　building　process　of　management　on　DSS,　the　main　parts　and　constructional　methods　were　decided.　The　system　was　designed　from　seven　parts:　integrated　road　traffic　safety　information　management　subsystem,　accident　causation　analysis　subsystem,　traffic　accident　prediction　subsystem,　traffic　incident　management　and　alarming　in　advance　subsystem,　safety　evaluation　subsystem,　safety　countermeasures　subsystem,　economic　analysis　and　decision　subsystem.　The　data　management　and　realization,　modal　realization　and　man-machine　interface　were　designed,　an　application　example　was　studied　with　integrating　program　development　flow.　6　figs,　11　refs.