According to rapid developments in data communication, we have being used every infromation with ease. In receiving and transmitting the infromation acquired, it is being needed to transmit it with minimizing bits if possible. Therefore this paper suggests the efficient coding system, that is, OCM(Octal-Compact Mapping) technique. In case of average-case, it has 3.5bytes in entropy with 8 symbols. This means it is compressed more than at least 1 byte as compared with another coding techniques. It decreases the redundancy of data and is superior to another data compression techniques.