A system for transmitting an image information signal which continuously forms a temporally correlated group of image planes is arranged to divide each image plane portion of the image information signal into a plurality of blocks; to have a plurality of different information transmitting modes of transmitting the image information signal in different degrees of information density including a mode in which a present image plane portion of the image information signal is not transmitted; to form a transmitting information signal on the basis of applicable one of the plurality of the different information transmitting modes; to generate for each of the blocks a transmitting mode signal including information indicating use or nonuse of the information transmitting mode in which the present image plane portion of the image information signal is not transmitted; and to transmit the transmitting information signal and the transmitting mode signal in a multiplexing manner.
