MIMO (Multi Input Multi Output) technology is widely used in current wireless communication standard. Compared with SISO (Single Input Single Output) technology, MIMO can provide higher data rate and better communication quality. This thesis mainly focus on improving the communication quality of wireless local area network(WLAN) using wireless communication device with MIMO technology and Multi-polarized antenna. Meanwhile, an WLAN indoor plan example will be studied. The original WLAN indoor plan will be improved by using the device mentioned above. The improvement will be based the the evaluation results.