Cricothyroid and sternohyoid muscle activities were examined in a male adult subject of Mandarin Chinese. The main interest of the present study is to know the neural organization for production of light tone. Syllables with light tone and syllables with tone 4 are selected for investigation. Since the latter tone type is falling as well as that of the light tone, the comparative study of the EMG patterns for production of these two tone types should give us some physiological correlates of the light tone production. Suppression of the cricothyroid muscle and activation of the sternohyoid muscle were observed in both tone types. However, the degree of suppression of the cricothyroid activity is less marked in the light tone than in the tone 4. Physiological interpretation is discussed.