In recent years, confronted with globalization, many Japanese companies introduce Result-based Human Resource Management and irregularl employment. As a result, the employee turnover rate is increasing in Japan and these companies faced problems to maintain a long-term and stable employment relationship with workers who possess the necessary skill and motivation for the job. Such Changes have altered employees’ mental orientation for employment and influence their organizational behaviors. Under such circumstances, Psychological Contract Theory plays an important role in helping us explore the influence of employment-relationship changes on several rganizational13;behaviors. The research of psychological contract in Japan began in end of the 20th century and attracted the attention of a few researchers during this decade. This research note aims to produce a lead for future theoretical and empirical research projects on psychological contract theory. The paper presents what we know about psychological contract theory including literature reviews and about theoretical analysis. Through the review of the earlier studies, I attempt to discuss the limitations of previous researches and future directions.