Document management is one of the fastest growing areas of information management. Most conventional approaches assign keywords to documents so that documents can also be retrieved through keywords. The management of data and documents are different. For example, documents have to be appeared in the full contents unlike the selected attributes are retrieved in the data queries. Also, the documents may not relevant even the values of specified attributes are identical. Moreover, documents may be related even they do not have the same keyword value. This study uses an associated knowledge rule algorithm, revised from Apriori algorithm, and classification scheme to discover the relationship between keywords of documents. The proposed algorithm can retrieve related documents without matching specified keywords in users\u27 queries