We analyzed the prosodic features of "anger," "joy," and "sadness" depending on the degree of the emotion for expressions in Japanese speech. The degrees of emotion were "neutral," "light," "medium" and "strong." Four announcers (two male and two female) uttered 6 words five times, and the parameters of the prosodic features were speech rate and fundamental frequency. The analysis results showed the following. (1) The most significant prosodic feature for expressing "anger" was to enhance the fundamental frequency. (2) The most significant prosodic feature for expressing "joy" was to enhance the fundamental frequency. A significant feature was to emphasize the accent. (3) As a method of expressing "sadness," the female speakers made their pitch low and suppressed accents (i.e., flattened the F0 pattern). The male speakers did not seem to use prosodic features to express "sadness."