ERP is experiencing the transformation that will make it highly integrated, more intelligent, web-enabled, and even wireless. The ERP system is becoming the system with high vulnerability in which the security is critical for it to operate. This paper shows the security policy of ERP system. ERP system is the technology that provides the unified business function to the organization by integrating the core business processes. The significant ERP policy is proposed that filtering by uniting DB application firewall with web application firewall. At second this paper researches security system with password controls by a comparison of password techniques for multi-lever authentication mechanism. Third it is explained how to sort and keep off spam-mail with three prevention way by server level, network structure level, client level. Finally it is discussed that security problem for ERP-ASP service and EDMS(Enterprise Document Management System), KMS(Knowledge Management System). Also the distribution of ERP system components over P2P(Peer to Peer) networks is considered.