Abstract
Disease name thesaurus has been compiled by using"Word Clearing", probably the first thesaurus management system in Japan. It assigns a unique code on individual disease concept and the relation between disease names can be understood from the code. Some of useful functions of"Word Clearing" are (1) displaying a hierarchial relation between terms visually in one frame(synonyms, broader terms, narrower terms and related terms);(2) checking of hierarchial relation of terms;(3) automatically formation of search statements. It has high value since there is a growing need toward user-friendly thesaurus. Author indicates a direction of future thesaurus:thesaurus should not be a slave of a database, and must have wide applicabilites to varius database management systems.
