The related literatures can have different understanding because demand purposes are different,in the sci-tech novelty retrieval sense,the related literatures must be consistent with its job requirements.

Text mining is the kernel of the disjoint literature-based knowledge discovery.

Based on the analysis of the existing ranking methods of B collection of disjoint literaturebased discovery,this article proposes the two way frequency-based ranking method according to the co-occurrence theory and the subject relative-degree.

Based on the analysis of the existing ranking method of B collection of disjoint literature-based knowledge discovery,this article proposes a co-MeSH density weighting-based B ranking method according to the co-occurrence theory and the subject relativity.

This paper expounds the description principle of relevant western literatures,and illustrates the principles and key points of relevant literature cataloguing with actual examples.

Related Articles Retrieval based on biomedical Related Articles Database (RAD), as an important tool for improving the intelligent level of biomedical Literature Retrieval System, is significant to meet the knowledge demands of clinical, teaching and research staff in the field of medicine and health.