This paper proposes a methodology for acquiring the top k highest-ranking SCORM-compliant teaching materials on grid environments, for a given query. Especially, the ranking criterion combines the relevance of the document and the efficiency of transmission. This methodology consists of three steps. First, the ranking function of each Learning Object Repository (LOR) is evaluated. Next, the number of documents to be retrieved from each LOR is decided according to the Ranking Ratio. Finally, the k documents are retrieved from the grid. To verify this approach, a prototype of the retrieval system was built on a grid testbed. Experimental results showed that the proposed approach can retrieve satisfactory teaching materials for users.