<div ng-controller="ngSelect">

    <select ng-model="vm.selectVal" ng-options="o.title for o in vm.optionsData">

        <option value="">请选择</option>

    </select>

</div>

var app = angular.module("app",[]);

app.controller("ngSelect",function($scope){

    var vm = $scope.vm = {};

    //数组对象用来给ng-options遍历

    vm.optionsData = [{

        title : "angularJs"

    },{

        title : "emberJs"

    },{

        title : "backboneJs"

    },{

        title : "knockoutJs"

    }];

})

<select ng-model="vm.selectVal" ng-options="o.id as o.title for o in vm.optionsData" ng-change="selectChange()">

    <option value="">请选择</option>

</select>

vm.optionsData = [{

    id : 4543,

    title : "angularJs"

},{

    id : 546,

    title : "emberJs"

},{

    id : 456,

    title : "backboneJs"

},{

    id : 75,

    title : "knockoutJs"

}];

$scope.selectChange = function(){

    //添加了ng-change事件来试试id值的输出

    console.log(vm.selectVal);

}