In this paper, we proposed a new source coding method based on Lempel-Ziv-Welch(LZW) method. Our proposed method assigns variable-length codewords instead of LZW's fixed-length codewords. Proposed method has a Least-Recently-Used(LRU) deletion heuristic queuing buffer whose each entry has a different parsed string. The queuing buffer is sorted on the rule of Move-to-Front(MTF) for each time of encoding/decoding. Proposed coding rule is that in the shallower entry of the queuing buffer a parsed string is, the shorter length of codeword is assigned for it. In result, proposed method yields better performance of compression ratio without losing the characteristics of LZW.