The purpose of this study was to reflect creative dimension of arts in arts psychotherapy mainly on cognitive approach to arts. First of all main theories and characteristics of cognitive approach were examined, which is important in creative dimension of arts. According to this approach, arts were regarded as fundamental methods of cognition by which perceptive reasoning is made, and they play a very momentous cognitive role in our understanding and constructing the world surrounding us. In particular the unique cognitive functions of arts that are flexible, integrative and creative play an effective role in the process of discovery and creation. And these characteristics of arts provide an essential theoretical basis explaining why arts have therapeutic effects in arts psychotherapies. The following creative dimensions were provided as the result of the discussion. First, arts stimulate our desire to create, pursue, and modify. Second, arts stimulate reasoning by promoting thoughtful and broad thinking. Third, arts enable us to think integrative. Fourth, arts promote flexible thinking. Fifth, arts promote creative thinking. Finally arts enable us to know what insightful experience is. It is expected that the studies, like this, will contribute to strengthening theoretical and practical basis by providing a theoretical ground for why arts have therapeutic effects and even to securing academic identity of arts psychotherapy.