This study aims at revealing the experiential structure of spontaneity in psychodrama using a phenomenological method. Five participants with the experience of being spontaneous auxiliaries in psychodrama were chosen and invited to describe their experience. Phenomenological analysis (Lee & Lai, 2009) was applied to the descriptions of experience. Two main findings were obtained. 1. The experiential structure of spontaneity in psychodrama consisted of two dimensions of behaviors. One was the vertical dimension, indicating the words-bodily feelings connection, and the other was the horizontal dimension, indicating the interpersonal verbal and nonverbal communication. Through the scene-setting, playing the role, or interacting with the protagonist, the auxiliaries in psychodrama came to experience psychological or bodily feelings and they might also feel urgent to speak out the experience in interpersonal realms. The auxiliaries experience themselves as being spontaneous as they can express what they felt bodily and psychologically. 2. In the experiential structure of spontaneity, the experience and expression of bodily feelings were the key. Through this study, various significant features regarding spontaneity in psychodrama were clarified.