Abstract. Multimodal interactive systems offer a flexibility of interaction that increases their complexity. ICARE is a component-based approach to specify and develop multimodal interfaces using a fusion mechanism in a modality independent way. ICARE being reused to produce several multimodal applications, we want to ensure the correctness of its fusion mechanism. So we validate it using a test architecture based on Java technologies. This paper presents our validation approach, its results, its advantges and its limits.