An image information transmitting/receiving apparatus for time and cost-saving repetitive transmission. In facsimile communication, image data where further information is added to previously-transmitted image data is often received. In the present apparatus, the original image data is stored, and only difference data from the original image data is transmitted, thus the whole image can be reproduced at the receiving side, using the received difference data. Upon transmitting the difference image information, identification information identifying the difference image information is added to the difference information, and the entire image data to be received by the receiving side is stored. Upon receiving the difference image information, the received difference information is combined with the stored image data, and an image is reproduced based on the combined image data. Further, the image data used for image reproduction is stored as original image data for the next transmission. In this manner, once the original image data is stored, only difference data is sent at each subsequent transmission, thus reducing the amount of transmission data.