This paper reviews the main efforts in the research of harvesting metadata records in distributed digital libraries environment. The advantages and remained issues are briefly presented in order to have a comparison in our new approaches. A general scenario of integrating metadata in Peer-to-Peer based environment is introduced with respect to three situations, such as sharing a common schema; different schema but in the same community; different schema and community. There are many issues in the framework, whilst in this paper we present our approaches in extending OAI metadata harvesting protocol to fulfill the requirements in P2P network and adopting popular inference engine for heterogeneous schema mappings. Additionally, a rough idea is also presented for locating peer in such a framework.