This　paper　performed　a　study　on　urban　signalized　T-Intersection.　By　investigating　a　number　of　intersections　to　determine　the　motor　vehicle　speed,　the　intersection　of　internal　conflict　and　so　on　as　criterions　of　the　level　of　service　of　safety　(LOSS)　evaluation　criteria.　This　article　used　an　urban　T-Intersection　in　front　of　the　west　gate　of　Beijing　University　of　technology　as　an　example,　analyzed　the　data　of　samples　collected　to　evaluate　the　security　service　in　the　intersection　and　established　model　of　the　LOSS　based　on　the　conflicts　between　the　motor　vehicle　and　motor　vehicles,　motor　vehicles　and　bicycles,　motor　vehicle　and　pedestrian.　Finally,　the　LOSS　is　divided　into　three　grades　A∼C　and　model　of　LOSS　is　applied　to　evaluate　the　security　services　of　the　intersection.　©　2011　ASCE.