The purpose of this study was to classify icebreaking in workshops. The data were nine books introducing icebreaking. Based on book chapters, we undertook a major classification and made minor classifications based on the heading of the page introducing each icebreaking. The main results were as follows: (1) three major categories and ten small categories were identified. (2) In order to understand the whole picture of icebreaking, it might be effective to show classification through the “formation” as well as through “human relationships” and “purposes.” (3) “Preparation”, “required time”, “formation”, are “number of people” are criterion for selecting an effective icebreaking.