Abstract: A expert system for the computer aided design of the overall design of antitank missile systems (AMODES) is suggested. Knowledge base and its maintenance system are established; the inference system, inference interpreter system and evaluation system are designed. The system is assessed through an example. AMODES is adapted to multiple programming languages such as Turbo Prolog, FORTRAN and Turbo C. It can infer some design parameters, evaluate and decide the design outcomes, thus enabling designers to accomplish many design problems.