To　create　performance　models　of　complicated　systems,　object-oriented　modeling　methods　based　on　POOSL　were　proposed.　The　modeling　process　was　divided　into　three　stages:　object-oriented　system　analysis,　model　design　and　model　realization.　Statechart　diagram,　sequence　diagram　and　class　diagram　were　applied　in　the　modeling　realization　stage.　Based　on　the　object-oriented　modeling　technique,　the　performance　model　of　IEEE　802.11　MAC　protocol　was　built　using　POOSL.　Through　the　simulation　of　the　model,　the　influence　of　the　parameters　such　as　minimum　contention　window　and　number　of　active　stations　on　the　performance　metrics　such　as　valid　throughput　and　average　frame　delay　in　ad　hoc　network　were　given.　Simulation　results　show　that　the　object-oriented　modeling　technique　can　be　applied　to　performance　modeling　effectively.