This paper describes data sharing system for the study of Japanese Classical Literature, mainly from the view of data creation using XML/SGML. We adopted XML/SGML because XML/SGML data serves as an excellent intermediate format for data storage, data interchange, and information retrieva1. First our own markup system (KOKIN rules) for building full-text data will be explained in detail, then our trial conversion of KOKIN-based data to XML/SGML is discussed. Finally collaboration system based on Z39.50 and Dublin Core metadata to share variety kinds of data is summarized.