Calculating　accurate　regional　phase　travel-times　through　regional　3D　velocity　models　constructed　is　one　of　the　important　means　to　improve　regional　seismic　event　location　accuracy.　Using　local　1D　model,　ground　truth　(GT)　events　and　geological　data,　construction　of　3D　velocity　model　is　carried　out　as　follows:　First,　we　construct　an　initial　3D　velocity　structure　through　Kriging　method　using　some　local　1D　velocity　models;　then,　modify　it　repeatedly　by　GT　event　travel-times　and　geological　data　until　the　minimum　travel-time　bias　is　reached;　and　finally,　the　modified　3D　velocity　model　is　obtained.　Location　testing　is　performed　with　different　velocity　models.　It　shows　that　the　modified　3D　velocity　model　can　improve　regional　event　location　accuracy,　and　the　bias　of　epicenters　is　decreased　by　about　20%　statistically.