Abstract: C276 alloy is one of the candidate cladding materials in advanced nuclear power plants. In this work, the distributions of irradiation damage were calculated by the TRIM code about energy loss, target displacements and DPA of C276 irradiated by protons with energy of 10 and 20 MeV, and there were comparisons among them as well. The activation calculations of C276 were carried out with the FISPACT-2007 code at the same time. The activity, afterheat and contact dose rate during different cooling time after shutdown were described in detail. The result indicates that electronic energy loss is the main part of irradiation damage, high-energy protons get lower probability of collision. In the case of the same energy protons irradiation, the activation characteristics increase with increasing irradiation time. With the same irradiation time, high energy protons would have a greater impact on materials. This work will provide support for the molecular dynamics simulation and the planning of the proton irradiation project.