The paper gives an overview of the security issue on WiMAX, which is a new and hot research point for telecommunication and computer scientist. In the IEEE 802.11 technology, security was added later while IEEE 802.16 considered the security issues during the design of the protocol. However, security mechanism of the IEEE 802.16 still remains a question. WiMAX is relatively a new technology and does not deployed widely to justify the evidence of threats, risk and vulnerability in real situations. We also discuss how to apply neural cryptography at WiMAX application in the end.