Abstract: An individual information protecting card is formed by multiple image frequency transformation of the invention is a system utilizing a simplicity of bar cade and an image property of hologram in complexity which is a frequency card being simple in construction. Data to be recorded to the protecting card utilizes an image-based system different from existing numeric cipher code-based system. The image to be used can use not only use a binary image for letters, but also can use continuous grey level as photograph. However, the difference is not in the frequency card exposed externally. Accordingly, expansion to image protecting form is possible and application to a system for managing an information by allocating special image information by individual and by article list is possible. Output of card construction system is made by a reading card possessed by a system operator, a resolution card for increasing of resolution, and user's card being a protecting card.