In order to clarify the effect of the taste of food on the masticatory movements, 16 healthy subjects, aged 22 to 28 years (average age 25.8 years) were asked to chew gummy-jelly of different flavors and their masseter muscular activities were investigated. Three types of gummy-jelly with varying degrees of bitterness ranging from, not bitter, slightly bitter, to bitter were chewed on the habitual chewing side for 20 seconds and the masseter muscular activities on the habitual side were measured by EMG. After the masseter muscular activities were observed, the duration, interval and cycle time of the masseter muscular activities, the integral value of all cycles and the integral value per cycle were calculated and compared among the three foods. The duration, interval, and cycle time of the masseter muscular activities was the shortest during chewing non-bitter gummy-jelly and increased with the degree of bitterness of the gummy-jelly. Statistically significant differences were found between chewing of non-bitter and bitter gummy-jelly. However, no significant difference was found in the total integral value and the integral value per cycle of the masseter muscular activities. From these results it was concluded that the difference in the degree of bitterness of the gummy-jelly affects the chewing rhythm, but does not affect the amount of the masseter muscular activities.