Codeword index assignment (CIA) is a key issue to vector quantization (VQ) In the communication system with channel crrors that will introduce extra distortions in the decoding step. Tabu search algorithm (TSA) has been success-fully used to solve the codeword index assignment for the purpose of minimizing the extra distortions due to blt errors. In this paper, simulated annealing (SA) technique is introduced In the iteration of TSA to Improve the convergence performance, Experimental results show that the modified tabu search algorithm (MTSA) is superior to TSA by evaluating the performance of channel distortion after the same number of iterations.