Abstract: The network topology discovery is indispensable for a network management system．Visualizing the topology of complex network systems is an efficient way to grasp the topological structure of the network quickly．A new visualization method,which applies to the display of the topology of middle or small scale network,was proposed．It visualized the topology based on hierarchical structure with the major devices being separated from the minor devices in the different hierarchy．The major devices were hierarchically displayed on screen from top to bottom．This method also allowed the administrator to change the layout of the topology display flexibly．The basic concept and important techniques in implementing the method were presented．