Abstract: Refinement of software architecture deals with mapping and transformation between architectural models at different abstraction levels. This paper reviews current researches on software architecture refinement, analyzes their inadequacies, and then proposes a new concept of interactive action refinement of software architecture based on πADL architecture description language, defines the formal specification method and principles of interactive action refinement, develops a refinement reasoning algorithm, which can preserve the higher-level architectural behavior properties across refinement hierarchies and generates lower-level architectures automatically. Interactive action refinement can effectively eliminate the mismatches of abstraction levels between components and their interactive actions that occur in the architectural refinement process. A case study shows the validity of the proposed method.