The purpose of this study is to throw light on the significance of the co-facilitator relationship in the encounter group. A questionnaire was administered to 50 encounter group facilitators. The questionnaire asks the subjects to rate two groups; good co-facilitator relationship group and a bad one, by means of a group process scale which was constructed by Hayashi (1989) to rate the encounter group developmental phase. There proved to be a significant difference between the two groups in each of thirteen items as well as in the scale as a whole. And the rating of the good co-facilitator relationship group was higher than that of the bad one, The findings have confirmed the significance of the co-facilitator relationship in the encounter group process.