Regression testing has been a popular quality-assurance technique. Most regression testing techniques are based on code or software design. This paper proposes a scenario-based functional regression testing, which is based on end-to-end (E2E) integration test scenarios. The test scenarios are first represented in a template model that embodies both test dependency and traceability. By using test dependency information, one can obtain a test slicing algorithm to detect the scenarios that are affected and thus they are candidates for regression testing. By using traceability information, one can find affected components and their associated test scenarios and test cases for regression testing. With the same dependency and traceability information one can use the ripple effect analysis to identify all affected, including directly or indirectly, scenarios and thus the set of test cases can be selected for regression testing. This paper also provides several alternative test-case selection approaches and a hybrid approach to meet various requirements. A web-based tool has been developed to support these regression testing tasks.