Abstract: The PNP input bipolar operational amplifiers were irradiated with ⁶⁰Co γ rays, 3 MeV protons and 10 MeV protons respectively at different biases to determine the correlation of the radiation damage induced by γ rays and protons. The comparison of protons with ⁶⁰Co γ rays shows that the proton radiation can induce both displacement and ionization damage, and 10 MeV protons can induce more damage than 3 MeV protons under the same absorbed dose. The biases have little effect on the proton radiation damage.