The Autonomous Decentralized Database System (ADDS) has been proposed in the background of e-business in respect to the dynamic and heterogeneous requirements of the users. With the rapid development of information technology, different companies in the field of e-business are supposed to cooperate in order to cope with the continuous changing demands fro services in a dynamic market. In a diversified environment of service provision and service access, the ADDS provides flexibility to integrate heterogeneous and autonomous systems while assuring the timeliness and high availability. A loosely-consistency management technology confers autonomy to each site for updating while maintaining the consistency of the whole system. Moreover, a background coordination technology, by utilizing a mobile agent, has been devised to permit the sites can coordinate and cooperate each other while conferring the online property. The use of mobile agent, however, is critical and requires reliability in regard to mobile agent failures that may lead to bad response time and hence the availability of the system may lost. In this paper, a fault tolerance technology is proposed in order that the system autonomously detect and recover the fault of the mobile agent due to a failure in a transmission link, site or bug in the software. The effectiveness of the proposition is shown by simulation.