In　this　paper,　we　try　to　evaluate　the　state　of　mountain　highway　network　traffic　by　using　data　collected　by　a　fixed　detector　and　using　catastrophic　theory　as　the　criteria.　Flow　and　Speed　at　the　pivotal　intersections　and　segments　on　the　mountain　highway　are　considered　to　be　the　characterization　of　traffic　anomalies.　We　will　find　the　abnormal　road　section　and　analyze　the　inducement.　Finally,　part　of　108　national　road　is　used　as　the　example　to　validate　the　availability　of　the　method.　The　results　will　be　of　great　assistance　for　mountain　highway　maintenance.　©　2010　ASCE.