This paper presents an amphibian service-oriented agent model (SOAM) to address three design issues facing modern distributed information systems: autonomy, distribution, and heterogeneity. This work incorporates the service-oriented design paradigm, agent-oriented design paradigm, and Web service technology as supporting pillars by extending the coordinated intelligent rational agent (CIR-Agent) model so that agents can survive not only in agent-oriented environments but also in service-oriented environments. The feasibility of the proposed approach has been demonstrated through a prototype system in the distributed manufacturing scheduling domain.