Abstract:ARP attack is a potential safety problems often encountered in a complex computer network environment.Although it is not a virus, but the harm it as much as computer viruses,Ranging from slow speed and even cause paralysis, while in the disclosure of user information,A large number of computer users suffer,Most antivirus software can not solve this problem。In this article,We will start working principle of ARP,Analysis on the network using ARP spoofing to disguise the principle of attack and determine whether the attack suffered a ARP and prevention and handling of ARP attacks.