This paper introduces a management information system to organize the production of heavy duty trucks in multi-varieties, its structure and its main functions.On the basis of computers, this management information system has been designed as a multi-databases and multi-functions system. Every database has at least one Key-Field. The communication between any two databases can be performed through their Key-Fields. It has been proved in practice that the design of this system is successful.The use of this system has solved a lot of problems which were not solved before. It provides an efficient measure for raising the management level of the enterprise.