The present invention relates to a concatenated convolutional encoder and decoder for the next generation mobile communication system requiring a high performance channel coding, in particular to a concatenated convolutional encoder and decoder of a mobile communication system which is capable of providing a dual mode encoder and decoder for supporting both a parallel concatenated convolutional code and a serially concatenated convolutional code and improving the performance of the system by using punctured and thrown away sequence in a convolutional encoder. The present invention can show stable performance regardless of SNR, accordingly the credibility of the system can increase.