Abstract: ACBM is a Boyer-Moore like algorithm applied to a set of keywords held in an Aho-Corassick like keyword tree that overlays common prefixes of the keywords. The algorithm takes the best characteristics of both the Boyer-Moore and Aho-Corasick. Based on the idea of Boyer-Moore-Horspool, we make an improvement to AC-BM algorithm. In the improved version, the Good Prefix Shift is not performed, the Bad Character Shift function is improved, the Goto procedure is also modified which do not keep the parameters of Good Prefix Shift and Bad Character Shift.