Simple Network Management Protocol (SNMP) is the most widely-used network management protocol for TCP/IP-based networks. The functionality of SNMP was enhanced with the publication of SNMPv2. However, both versions of SNMPv1 and SNMPv2 lack security features, notably authentication and privacy. The SNMPv3 solves these deficiencies but it has some inefficiency to deal with the access, service refusal, or unstable action. On the other hand, XML is being used to describe components and applications in a vendor and language neutral. In this paper, we propose a policy-based SNMP security management architecture using XML. We propose a secure network management protocol that adopts the policy-based network management and the XML security features to the existing SNMPv3.