Wireless sensor networks is a rising subject to research and improvement, The advances and traits in Wireless Communication technology have made the deployment of small, low fee wireless sensor nodes connected through a wireless medium, known as Wireless Sensor Networks (WSNs), technically and economically possible. These WSNs have were given several packages in diverse fields like an army, environmental monitoring, fitness, enterprise and so on. Security has already ended up a primary subject for WSNs because of the wide utility of WSNs in security-vital regions. In this paper, we check out the security-related troubles and demanding situations in wi-fi sensor networks. We identify the security threats, overview proposed safety mechanisms for wi-fi sensor networks