The　strategies　of　two　duopoly　ports　which　are　characterized　by　different　quality,　network　externality　coefficient,　compatibility,　switch　costs　were　studied　after　Hotelling　model　with　Vertical　product　differentiation　(port　logistic　service　differentiation)　and　quadratic　transport　costs　was　introduced.　For　two　ports,　their　locations　and　competitive　in　price　were　chose　simultaneously.　Equilibrium　market　strategies　of　duopoly　ports　with　Horizontal　and　Vertical　product　differentiation　are　obtained.　Under　the　assumption　that　duopoly　ports　would　choose　their　maximal　horizontal　product　differentiation　(maximal　location　differentiation)the　influence　of　network　externality　coefficient,　compatibility　coefficient　and　switch　costs　on　the　duopoly＇　competition　equilibrium　was　analyzed.　According　to　the　results,　in　competitive　environment,　port　should　concern　its　own　price　advantage　change,　which　will　raise　with　the　increase　of　its　own　network　externality　coefficient,　compatibility,　switch　costs　respectively　and　which　will　reduce　with　the　increase　of　competitor＇s　network　externality　coefficient,　compatibility,　switch　costs　respectively.　©　2011　IEEE.