An apparatus and method for providing handover support information in a mobile communication system are provided. A method for an Base Station (BS) to provide information necessary for measurement report trigger performance to a Mobile Station (MS) after the MS determines neighboring BSs in a mobile communication system includes, in a case where the MS is an active mode MS, providing a Time To Trigger (TTT) independently by a specific neighboring BS to the active mode MS and, in a case where the MS is an idle mode MS, providing a reselection time period (Treselection) independently by the specific neighboring BS to the idle mode MS.