Abstract: In this paper,a distributed microcomputer system（MDS）is presented with emphasis on its interconnection construction,communication interfaces,communication mechanisms and design ideas and implementation methods of the distributed operating system MDS/DOS Based on MS-DOS,MDS/DOS is constructed by adding a distribuled communication and resources management modale（DCRM）and a distributed command imerpreter（DCI）,which is compatible with MS-DOS The MDS system has realized fundamental functions of a distributed system.