PURPOSE: To attain the automatic preparation of a form dictionary for character recognition by analyzing the form structure of characters from plural pictures representing the same character, obtaining a general structural feature, checking the general structural feature with the similarity of the structural feature already classified in the dictionary, incorporating the similar one to the class of it and making the class newly when it is not similar.

CONSTITUTION: A picture input part 11 reads pictures representing the same character successively. A skeleton line is extracted on the respective pictures having the same character read by the picture input part 11 in a skeleton line extracting part 12. The form structure of the character by the general structure of a curve is analyzed successively on the respective skeleton line pictures in a curve structure analyzing part 13. The similarity of the curve structure outputted form the curve structure analyzing part 13 newly and the curve structure already classified in a dictionary 15 is checked in a dictionary preparing part 14, when the similar one is present, the class of it is incorporated and when the similar one is not present on the existing class, the class is made newly. Thus, the automatic preparation of the form dictionary for character recognition by structural procedure is attained and the development of a character recognizing system is facilitated.