Although archival documentation is the core term in Archival Document Compilation Science, there have been different opinions on its definition since it was first proposed in 1981.In this paper, six representative definitions of archival documentation are firstly sorted out, and then the author compares and analyzes them from following four perspectives: Whether archival documents are development objects or interpretation objects, compilation objects or compilation results,whether archival documentation or the components of archival documentation are only the part of archives with high value, the dual disciplinary attributes of Archival Science and the definition of archival documents. Finally, the definition that can reflect the current discipline development and the needs of compilation practice is proposed.