With　the　increased　emphasis　on　traffic　safety　in　recent　years,　vehicle　performance　has　been　improved　through　extensive　research.　However,　recent　research　on　the　stopping　sight　distance　(SSD)　on　two-lane　highway　in　the　mountain　area　has　not　kept　pace　with　these　vehicle　improvements.　Several　models　have　been　developed　to　determine　the　minimum　stopping　sight　distance　required　for　safe　and　efficient　operation　on　two-lane　highways.　However,　these　models　need　to　be　revised　to　determine　the　stopping　sight　distance　requirements　more　accurately　and　to　closely　match　field　observations.　In　this　paper,　the　aim　is　to　look　for　the　relationship　between　reaction　time　and　different　driver　characters,　using　experimental　data　measured　by　RTK　GPS　receivers　and　LJ9102　testing　instrument　which　decides　complex　reaction.　Then　this　study　gives　the　reasonable　relationship　between　SSD　and　reaction　time　quantificationally　by　analyzing　the　real　static　state　and　dynamic　reaction　time　data.　The　result　show　the　widely　received　2.5s　for　SSD　is　less　than　the　minimum　stopping　sight　distance　required　for　safe　and　efficient　operation　on　two-lane　highway　in　the　mountain　area.　The　deficiency　was　found　to　increase　with　the　increase　in　design　speed.