In this paper, we describe a new word spotting algorithm based on forward decoding. In past studies, continuous dynamic programming[1] had been popular for word spotting. This algorithm which uses dynamic programming is considered to have a free start point and end point, and is controlled by some criterion; determining this criterion is very difficult. The proposed decoding algorithm basically performs comparison for the score of the last state of any word HMM. Therefore, it is expected to obtain a higher performance than continuous dynamic programming. Also we describe the problem of Viterbi decoding and explain that this algorithm may resolve the above problem.