ITU - T G.728 recommendation shows a low-delay speech coder at the bit - rate of 16kb/s, which is a kind of EELP speech coder and was worked out by the international Telecommunication Union in 1992. Based on a brief introduction to code-decode algorithm principles, this paper discusses, in detail, the real-time realization hardware designing and software development of LD-CELP algorithm of G. 728 on TMS320C6211 and the key technology in the design of system.