Human being can be defined in several ways. These are biological, psychological, social and religious, ethical and philosophical aspects. The first two viewpoints refer to the intrapersonal aspects and the last two viewpoints deal with the interpersonal aspects. In every aspect, introspection is very much important to understand him or herself and other person. In this paper, the author summarized the instruction from the oriental old classic books. By doing this process, the author suggested three ways to introspect himself：1) We have to read the old classic books on Wisdom and follow the teachings in those books. 2) Self-analysis may be one way to introspect him or herself. It is to understand his emotional response by way of thinking(reasoning). By repeating this process, affect and thinking can achieve harmony and balance. 3) Training analysis may help to introspect oneself. Qualified analysts may be of help. In order to understand the psychological aspect of patients, the psychiatrists should get insight into his own mind. In this aspect, introspection is the single most important factor in achieving insight.