This research aims to analyze business strategies of professional sports marketing companies which have properties of sports organizations in Korea, with a view to investigating into the nature of the business of the agencies and the characteristics of business models and to considering what kinds of suggestions such characteristics have for the development of professional sports marketing agencies in Korea. Professional sports marketing agencies do not simply acquire their property rights or act as a proxy in getting the property rights but also multiply opportunities for their business while acting as a proxy and developing extension commodities so as to maximize their profit, which is a core capability of sport businesses. Sports marketing businesses in Korea are characterized by dual structure: advertisement companies specializing in BTL (Below The Line)-centered promotion business, and sports marketing agencies specializing in the business focused on sports contents. This structure serves as an obstruction for Korean sports marketing agencies to build up their capabilities to maximize opportunities and extension.