Professional Ability Standard for University Instructor (Temporary), which clears and definites the aims and demands of professional development, still exists certain theoretical and realistic problems in practical application yet. With the introduction of professional ability development theory, and the study of relationship between professional development, professional ability development and professional development of university instructor, the four common difficulties existing in instructor's professional development at the present stage are analyzed. In addition, the instructor's professional development and approach to realize instructor's professionalization and specialization are elaborated in detail from five aspects, including job evaluation, capacity evaluation, professional organization, professional role and professional aspiration.