In ubiquitous computing environment' different kinds of system components including hardware elements' software components and network connections are required to cooperate with each other to provide services that fulfill user requirements. This paper proposes an agent-based middleware for ubiquitous environment that consists of computers and home electric appliances. The middleware' called AMUSE' can take QoS (quality of service) in ubiquitous environment into consideration by coping with not only user context but also resource context' using agent-based computing technology. In this paper we describe concept' design and initial implementation of AMUSE. Simulation results of experimental ubiquitous service using AMUSE has been shown to prove the effectiveness of our proposed scheme. Additionally' we show the initial implementation of multimedia communication application based on AMUSE to confirm the feasibility and effectiveness of our scheme.