In this paper, the reduction method of number of parameters in the segmental-feature HMM (SFHMM) can be considered. It is reported that the SFHMM shows better results than conventional HMM in the previous studies. However, its number of parameters is greater than that of HMM. Therefore, there is a need for new approach that reduces the number of parameters. The trajectories are used for the acoustic features of the SFHMM. In general, trajectory can be separated by the trend and location. Since the trend means the variation of segmental features and occupies the large portion of SFHMM, if the trend is shared, the number of parameters of SFHMM maybe decreases. We consider the trend tying of segmental features by the quantization. The experiments are performed on TIMIT corpus to examine the effectiveness of the trend tying.