Implementation of project management in library is a transformation process of its organizational structure. By redesigning the staff performance appraisal system along the process of projectification, it will facilitate reforming the organization and bringing forth innovations for enhancing service efficiency. By reviewing the differences of organizational structures and performance appraisal systems between the functional organizational structure and the matrix organizational structure,this paper proposes a unified appraisal model with operational procedure and relevant measurements. The new model will take both the functional performance and project performance into account and truly reflect a library staff’s real performance in his/her work. Therefore,it is worth of further research and continuous refinement.