This paper reviews the main efforts in integrating metadata records in distributed digital libraries environment. Each of these solutions does meet some of the requirements of distributed library services somehow, but further study are still needed in some issues, such as limitation on the capacity of collections, retrieval of content-related records built in different metadata formats. In order to alleviate the problem, a novel super-peer based infrastructure for integrating metadata records in distributed and heterogeneous environment is introduced with respect to three situations, namely, sharing a common schema; in different schemata but in same community; in different schema and community. This paper sequentially describes feasible solutions according to these scenarios before coming to the conclusion.