PURPOSE: To hierarchically express a document record by permitting text information to have information of subordinate record by utilizing a data base system.

CONSTITUTION: At the time of preparing text information, a text information generating means 7 is started to store information in the text information field 2 of a text record 6. At the time of setting the subordination of text information, a subordinate text information editing means 8 is started to store information in a subordinate text recording start position field 3 and an end position field 4. At the time of referring text information, a text information reference means 9 is started to edit and supply the content of the text information field 2 and that of a subordinate text record position field 5.