Abstract: G.729 speech codec (encoder and decoder) algorithm and the TMS320VC549 fixed-point DSP (Digital Signal Processing) chip are briefly described in this paper. We put our emphasis on the hardware and software design of the low bit rate speech codec based on TMS320VC549 chip. Also, some key techniques for the real-time implementation of the complex algorithm on fixed-point DSP (Digital Signal Processor) are discussed. The results show that the real-time implementation of G.729 speech coder on fixed-point DSP can produce 8kb/s low bit rate, lower algorithm delay and toll-quality speech.