Disclosed is a managing architecture and diagnostic method for remote configuration of heterogeneous local networks, which includes at least one sub-network agent, a local area network (LAN) management module and a remote LAN module. Each sub-network agent manages its sub-networks via its own management protocol, and collects the sub-networks' information. The LAN management module receives the requests from heterogeneous local networks via these sub-network agents, and converts the information associated with each request into a common information model (CIM) to seek a solution for each request. The remote LAN module receives the unsolved requests from the LAN management module via a channel, configures the heterogeneous local networks and uses compatible interface at a remote side to accomplish the management and diagnosis for the heterogeneous local networks.