PURPOSE: To increase the transmission volume per unit of a data compressed information signal.

CONSTITUTION: In the digital data transmission method where data (d) where at least a synchronizing signal and error correction codes d11 to d14 and d21 to d23 are added to a data compressed signal (c) is transmitted, respective information of a flag F indicating the existence of start address information d31 to d35, painters, and block numbers are stored when start address information d31 to d35 of partial information signals c1 to c5 constituting the signal (c) exist in partial data d1' to d4' constituting data d'; but only a flag F' indicating the non-existence is stored when start address information d31 to d35 don't exist there.