The　merging　zone　in　urban　expressway　is　easy　to　turn　into　a　traffic　bottleneck　just　because　of　the　complex　interaction　among　vehicles　there.　But　with　the　development　of　connected　vehicle　technology,　it　seems　that　this　problem　can　be　alleviated.　This　paper　designs　a　system　that　can　harmonize　the　interaction　among　connected　vehicles　in　the　merging　zone,　so　that　they　can　cross　this　region　in　a　smaller　cost-less　average　travel　time　and　average　fuel　consumption.　The　controller　of　the　system　receives　the　real-time　data　from　vehicles　periodically,　and　sends　instructions　of　the　computed　solution　back　to　them.　At　last,　Netlogo　is　utilized　to　act　as　a　simulation　platform　to　evaluate　the　proposed　system,　and　the　results　show　that　the　coordination　system　of　connected　vehicles　can　reduce　cost　significantly　in　the　merging　zone.