The primary purpose of this study is to develop a genetic algorithm based computer-aided roll pass optimal design (CAROD) system to support the generalized roll pass design for rod rolling, where the final products are round bars with different sizes. The system was developed to minimize the number of roll passes, decrease the trails and errors in industry, as well as extend the work range of multi-pass rolling systems for rod rolling. Parametric equations were established for geometrical modeling and graphic plotting, which can realize to the parametric transformation for roll pass design and optimization. A methodology based on a hybrid model was proposed to choose passes with different profiles for the multi-pass rod rolling system. In addition, an improved genetic algorithm (IGA) was employed for the optimization of roll passes. A MATLAB program was designed to achieve all these objectives. To reduce the complexity and computational burden of the software, some reliable empirical formulas were applied in this system. Finally, the proposed approach has been applied in a rod rolling system; through simulation and comparison of results against analytical solutions, numerical analysis and experimental data presented by other researchers, it was found that this system is reliable, effective and easier to use.