Abstract: Objective To investigate the activities of different soft and hard materials during right chewing masticatory muscles, describing the masticatory muscles of time domain and frequency domain features. Methods 11 experimental subjects who conform to the standards of measurement chew two materials of different soft and hard texture. Then record surface EMG of each bilateral temporalis anterior bundle, masseter, two bilateral anterior abdominal muscles, analysis to 5 kinds of characteristics of the study of EMG. Results When subjects chewing different soft and hard materials, all the EMG features in the bilateral anterior temporalis and masseter values had significant difference (P < 0.05). The results in bilateral digastric anterior abdominal except zero crossing rate have significant difference; median frequency on the right side of the masticatory muscle has decreased trend. Conclusion The anterior temporalis and masseter EMG active more intense when chewing hard objects; the right side of the masticatory muscles have obvious fatigue trend after chewing hard masticatory 30 cycles.