To provide a structured document processing system capable of displaying an original structured document as a group of optional and plural related documents 30 by allowing a user to only simply describe the conversion of structure.

A navigation converting part 13 generates a group of plural related documents 30 related by applying navigation data 300 to original document data. In this case, the data 300 includes data concerning a leading document 301 and a related document 302 having a hyper link related from the leading document concerning one group of related documents. After then, a style converting part 14 applies style data 400 to the group 30 of the plural related documents 30 generated by the part 13 to give good appearance. The result of this is displayed by a browser to trace a link to display the documents by an optional form.