A system for designing the stacking sequence of laminated composite plates using object-oriented programming system Smalltalk-80 was presented. In this design system, the stacking sequence of a laminated composite plate is optimized to reduct the actual strain to a value less than that required by the design under an applied load with the lowestply number subject to constraints in the stacking sequence. Two optimization approaches were provided. In the first approach, plies which most drastically reduced the actual strain of the composite plate were laminated one by one. In the second approach, based on the branch-and-bound procedure, the optimal solution to the stacking sequence problem was efficiently obtained.