The strength of the intraoral and extraoral muscles that assist the function of tooth and jaw movement during mastication is important for performing oral function. The aim of this study was to investigate the usefulness of gum chewing training to improve the swallowing and feeding function. In experiment 1, the differences in maximum tongue pressure (TP) and cheek pressure (CP) at the measurement time point for both groups with and without training were examined. We instructed subjects to perform gum chewing training 3 times daily for 3 months. TP and CP were measured before training and at 1, 2, and 3 months after starting training. In experiment 2, the changes of TP and CP based on the sex and duration of training were examined. The effect of the training was evaluated before training, at 2 weeks and 1, 2, and 3 months after starting training, and at 1 and 3 months after cessation of training. Experiment 1 showed TP and CP increased with the progress of continuous training. In experiment 2, TP and CP were higher in men than in women and markedly increased at 2 weeks and 1 month in both sexes. After cessation of training, TP and CP tended to decrease, but there was no significant difference between 3 months after starting training, and also significantly higher than before training. This study suggested that gum chewing training is a useful to improve the swallowing and feeding function.