1. A composite service control system resolving a conflict, the system comprising: a conflict set defining unit to classify and define an conflict set with respect to an application programming interface (API) that is called from each application, and define an explicit conflict set and an implicit conflict set with respect to an application; a determining unit to determine an application triggering condition of a new application that requests an application registration, and, when the determined application triggering condition is overlapped with an application triggering condition of an existing registered application, to determine whether an intersection between an explicit conflict set of the new application and an explicit conflict set of the existing application exists and whether an intersection between an implicit conflict set with respect to an API of the new application and an implicit conflict set with respect to an API of the existing application exists; and an application managing unit to report the application triggering condition and execution information of the existing application and to request a defining of a conflict resolution policy or a changed application triggering condition for the new application, when either of the intersections exist, and to store the application triggering condition and the execution information of the new application in an application information database, when the intersections do not exist or the conflict resolution policy has been defined.