In　order　to　analyze　the　performance　of　IEEE　802.11　wireless　communication　protocol,　a　performance　abstract　model　of　IEEE　802.11　protocol　was　built　base　on　POOSL　language　and　the　performance　was　analyzed　qualitatively　and　quantificationally　in　ad　hoc　network　and　WLAN　with　AP.　During　modeling,　the　protocol　was　abstracted　rationally.　Wireless　channel　was　successfully　simulated　and　the　two　accessing　methods　of　DCF　(basic　and　RTS/CTS)　were　simulated　accurately.　By　simulating,　the　effects　of　related　parameters　(the　number　of　STAs,　CWmin　and　frame　size)　on　performance　of　the　protocol　(valid　throughput,　average　delay　and　the　fairness　of　upload　and　download　throughput)　were　analyzed　and　got　the　optimist　values　of　the　CWmin.　©　2011　IEEE.