In this study, the problem of finding the shape of the strongest column which has the largest fundamental buckling load with equal length and volume for the clamped-clamped ends was purposed. It was also proved that the solutions of Tadjbakhsk & Keller (1962) and Olhoff & Rasmussen (1977)-Masur (1984) were not Optimum for columns with clamped ends. Then, true solution was obtained from Maur's analytical bimodal solution for clamped-clamped case by considering the crushing criteria. To test the accuracy of new optimized columns with clamped ends, both experimental and numerical studies were carried out. In this study, natural composite materials such as cedar and oak with variable circular cross-sections were used. Results of the optimum model proposed in this study were in agreement with results obtained by experimental data and numerical results.