MT-1 is a database management system based on dBASE-Ⅲ. It has a graphic language for data description and manipulation. It is a useful tool for the development of MISS. It is superior to dBASE-Ⅲ in many aspects，such as graphic user interface，data dictionary，views，data integrity and security，etc. This paper describes the architecture of MT-l，and discusses some issues of its design and implementation.