This study focuses on part of relationship between cost stickiness with a professional manager company based on agent theory and project theory. Also, analyze the effect of risk preference of professional managers on cost stickiness. Using the firm-year data from2000 to 2020 listed in Korea Stock Exchang(KSE), we find that the following results. First, the cost stickiness occurred in professional management companies. Second, professional management companies showed risk averse behavior. Third, cost stickiness could be alleviated in companies with professional managers who hate risk. These results can be said to support social perception that information imbalances and moral hazard, which arise from structural problems faced by professional management companies, are being accepted as natural phenomena. These results can be said to support the social perception that information imbalance and moral hazard of professional management companies are perceived as natural phenomena. In addition, suggests that in order to find an answer to the agent problem, it is necessary to prepare a practical system to alleviate various structural problems(Standards for evaluating inventory of professional managers, guaranteeing the employment period of professional managers, and guaranteeing the independence of professional managers) faced by professional management companies.