There are many cases that an organization needs to monitor the data and operations of its supervised departments, especially un-owned departments, which are managed by its own information systems. Distributed Heterogeneous Inspecting System (DHIS) is the system the organization used to monitor its supervised departments by inspecting their information systems. In DHIS, the inspected systems are generally distributed, heterogeneous, and constructed by different companies. DHIS has three key processes - to abstract core data sets and core operation sets, to collect these sets, and to inspect these collected sets. In this paper, we present the concept of DHIS, mathematical definition of DHIS, metadata method to solve the interoperability, security strategy for data tranferring, and a middleware-based solution of DHIS. We also describe an example of the inspecting system at Wenzhou custom.