Regarding increase of wireless network application, and fast development at these systems, security in such systems and networks has become a crucial matter. In this article, first different security methods of local wireless networks, as subsidiaries of wireless networks, are introduced and then the efficiency of so far introduced security methods such as WEP, WPA and WPAv2 are studied as well as their negative and positive aspects. The focus of this text is on IEEE security protocols including 802.1x and 802.11i, their functions and security levels. The privileges and shortcoming at the mentioned protocols would be discussed afterwards.