I have done a case study on group level based-organizational behavior textbooks published in Korea and USA. The objects are 'organizational behavior' by Su Yong Jung and 'organizational behavior' by Im Chang Hee in Korea, and 'organizational behavior' by Schermerhorn, Osborn, Uhl-Bien, & Hunt and 'organizational behavior' by Robbins, & Judge. The goal of this study is to identify the differences of the perspectives on the group level based-organizational behavior between Korean and American textbooks. This research finding shows that it is valid to classify organizational behavior into such categories as group & team, communication, decision making, leadership, power, and conflict & negotiation in the Korean textbooks for the better future study.