The aim of this dissertation is to study the inelastic collision of two protons. This collision occurs at energy and leads to forme a resonance state of . Because of their short lives, these resonance states decay quickly. So measuring the mass, width and the binding energy of the states are difficult. One of the unstable mode which may likely be produced in p-p collision is three-body system. In this thesis we applied T-Matrix method and calculated the differential cross section of the collision of two protons producing as a resonance state. From this cross section, we can calculate the invariant mass spectrum and find out the information of three-body system, including the mass and width.