This paper presents the design and implementation of the MAFTS(A Multi-Agent based Fault-Tolerance System), which is running on distributed multimedia object oriented environment. DOORAE(Distributed Object Oriented collaboRAtion Environment) is a good example of the foundation technology for a computerbased multimedia collaborative work that allows development of required application by combining many agents composed of units of functional module when user wishes to develop a new application field. MAFTS has been designed and implemented in DOORAE environment. It is a multi-agent system that is implemented with object oriented concept. The main idea is to detect an error by usingpolling method. This system detects an error by polling periodically processes with relation to sessions. And, it is to classzfL the type of errors automatically by using learning rules. The characteristic of this system is to use the same method to get back again it as it creates a session. (Key words: MAFTS, Fault-Tolerance System, DOORAE, multimedia collaborative work, multiagent, polling, learning rules.) ...