The purpose of this research was to investigate the difference in perception between clients(advertisers) and advertising agencies regarding the compensation systems of advertising agencies. Specifically, I have made efforts to examine the two groups’ extent of comprehension and incomprehension of this system by checking the existence of coorientation between advertisers and advertising agencies in respect of commission, fee, and incentive compensation system. As means of understanding the two groups’ difference in cognition, I have conducted a survey research on 106 advertisers and 116 advertising agencies-the two core interest groups. Moreover, by comparing the results of qualitative and quantitative research driven from in-depth interviews, I have drawn diversified conclusions. First, the coorientation of advertisers and advertising agencies towards the commission compensation system show a dissensus form. That is, the two groups’ cognition of the commission compensation system is different from each other. Congruency wise, advertisers and advertising agencies overestimated each others’ cognition of the commission compensation system. As for accuracy, the advertisers thought that the advertising agencies will prefer the system, while the advertising agencies had a fairly accurate idea of the advertisers’ cognition. If both the advertisers and advertising agencies favor the commission compensation system, the advertisers’ must first understand the advertising agencies at a deeper level and the advertising agencies must make their standpoint stronger and more persuasive. Second, in the case of the fee compensation system, the coorientation of advertisers and advertising agencies showed a ignorance form where the two groups overestimated each others’ cognition albeit their cognition actually was similar. As stated above, though the cognition of the advertiser match that of the advertising agency, the two groups are misperceiving and overestimating each other and showing a low congruency, thus bringing about mutual misunderstanding. Likewise for accuracy, the advertising agencies made a somewhat accurate assumption, whereas the advertisers misapprehended by overestimating the advertising agencies’ cognition of the fee compensation system. In conclusion, if the advertisers favor the fee compensation system, understanding between the two groups must take place first to decrease the level of misperception. Third, in the study of coorientation between advertisers and advertising agencies in regards of the incentive compensation system, the two groups coorientation showed a perfect consensus form. So to speak, the advertising agencies speculated the advertisers’ cognition of the incentive compensation system with accuracy, and likewise the advertisers too speculated the advertising agencies’ cognition accurately. Accordingly, both the two groups valued the incentive compensation system positively.