Business-to-Business (B2B) collaboration is becoming a pivotal way to bring today?s enterprises to success in the dynamically changing e-business environment. Though many business-to-business protocols are developed to support B2B interaction, none are generally accepted. A B2B system should support different B2B protocols dynamically to enable interaction between diverse enterprises. This paper proposes a framework for dynamic B2B interaction. A B2B transaction is divided into the interaction part and business implementation part to support flexible interaction. A component based system framework is proposed to support the B2B transaction execution. To support dynamic B2B services, dynamic component composition is required. Service and component notions are combined into a composable service component. The composition architecture is presented as well.