The　Ramp　Metering　(RM)　control　has　been　proven　to　be　an　effective　measure　for　improving　the　efficiency　of　expressway　operations.　owever,　due　to　the　complexity　of　network-wide　coordinated　RM　control　strategies,　the　model　parameters　in　the　control　model　requires　to　be　carefully　calibrated　and　optimized　using　the　local　traffic　data.　Establishing　a　quantitative　evaluation　method　with　reliable　Measurement　of　Effectiveness　(MOE)sis　also　a　crucial　step　for　optimizing　of　the　control　strategy.　In　this　research,　the　author　presents　the　procedures　of　optimizing　the　RM　control　strategy　for　implementing　network-wide　coordinated　control　as　well　as　its　evaluation　methods.　A　field-data　based　microscopic　simulation　site　was　built　to　reproduce　the　traffic　environment　and　implement　the　optimized　control　strategies.　It　was　proved　that　the　optimized　control　strategy　can　substantially　improve　the　efficiency　of　traffic　operations　in　the　implemented　network.　Therefore,　the　proposed　control　strategy　optimization　and　evaluation　process　is　validated.　©　(2014)　Trans　Tech　Publications,　Switzerland.