No matter what it is the academic field or the political field, the clash of civilizations generates profound international effects. However, the sidedness of recognition accompanies with the clash of civilizations. Since the clash of civilization is still popular at present, it is necessary to clarify its sidedness. This paper tries to made analyses from these aspects: difference and commonness of civilizations, root of civilizations clash, civilizations clash and civilizations internal clash, civilizations clash and cooperation, western civilizations’ prospect, non-western civilizations’ prospect.