In this study, Bragg curves of 160-220 MeV protons in the therapeutic energy range were calculated with Monte Carlo simulation. Ti(6)A(14)V, Co-Ni-Cr-Mo, Al2O3, Stainless Steel, Nital, Vitallium and Teflon were selected as biomaterials and the effect of biomaterial type and thickness on Bragg curve was investigated. A second peak is formed when protons pass from a less dense to a denser layer. The effect of the second peak and amplitude on the Bragg peak is also investigated in the slab head phantom. It has been seen that as the cortical bone thickness increases, the Bragg peak position decreases by 0.47-3.3%. As the proton energy increased, the amplitude of the second peak and the effect of the Bragg peak position decreased. The biomaterial which gives the closest results to the cortical bone among the biomaterials used was found to be Teflon.