The present study was designed to analyze the function of respiratory movements in speech. This study aimed specifically to analyze the voluntary abdominal movements just prior to speech and the speech utility. Subjects were 20 graduate students. They were asked under hypnosis to speak in the different mental states, such as resting tensed and relaxed periods with either strong or weak voice and in various tempos. From the results of factor analysis, following three factors were found: (a) dynamics, (b) speech utility, and (c) time. While the first factor was heavily loaded on the depth of abdominal movements and related to the strength and the tempo of speeches, the second factor was loaded on the method of holding speeches and the third factor on the timing of speeches.