The number of engine connecting rods currently in use worldwide has exceeded one billion; thus, the importance of their optimal design is unspoken.In this study, an original design criterion of an accurately lumping mass is used as a constraint for shape optimization, so as to achieve an optimal condition for both stress state and dynamics characteristics. Accordingly, we develop a preliminary conrod model described in section 7 with Eq.7 in mind, and then proceed with the optimization steps described in section 6. This conrod model 2 approach is a suitable scheme for achieving the dual optimization objective. It can be recognized from Figs. 11-17 that conrod model 2 can efficiently attain reasonably accurate results for dual optimization. Incidentally, the buckling effect is also an important issue affecting the conrod shape design; thus, it can be considered as another constraint for future detailed shape optimizations. Moreover, different design variables, boundary conditions and other variations may be considered in the optimization process as appropriate. Hopefully, the two-facet optimization scheme described herein will be useful for designing a connecting rod with improved overall performance.