Abstract: Component-based software engineering is increasingly being adopted for software development. Although much work has been proposed for building component-based systems, techniques for testing component-based systems have not been well developed. In this paper, we present a test model that depicts a generic infrastructure of component-based systems and suggests key test elements. The test model is realized using a Component Interaction Graph (CIG) in which the interactions and the dependence relationships among components are illustrated. By utilizing the CIG, we propose a family of test adequacy criteria which allow optimization of the balancing among budget, schedule, and quality requirements typically necessary in software development. The methodology proposed is efficient and effective, as demonstrated by promising results obtained from a case study.