This paper introduces a new research direction of applying psychological contract to study of the employment relationship in organizations of knowledge-based Employees. Generally, the employment relationships include three types of deals which are standard deals, position-based deals and idiosyncratic deals. Among those, idiosyncratic deals take more and more portions in today's organizations. This paper focuses on successful cases of applying psychological contract to study of these employment relationships. Furthermore, it introduces an important psychological contract framework and gives reference to the relevant domestic researches.