A transmitting system which comprises a transmission line, a transmitting apparatus connected to the transmission line, and a receiving apparatus connected to the transmission line, and transmits data between the transmitting apparatus and the receiving apparatus, wherein the transmitting apparatus comprises packet compressing means which receives input data comprising plural packets having identifiers as an input, identifies packets to be discarded and effective packets according to the identifiers, and outputs compression information indicating the number of continuously discarded packets and the effective packets to the transmission line, and the receiving apparatus comprises packet restoring means which receives the compression information and the effective packets which have been output from the transmitting apparatus, generates ineffective, packets which are as many as the discarded packets, and outputs the ineffective packets and the effective packets.