Quasi-nano filamentary copper-silver composites were irradiated and annealed to study irradiation degradation behavior. The specimen was irradiated in CT hole of HANARO of KAERI for 36 days at 320°C with the maximum neutron flux of 4.8x1020 n/cm2 (E>1.0 MeV). The gamma heating rate was in the range of 2.0-6.45 W/gm. Irradiation embrittlement was observed. Hardness determined by nano-indentation technique were 32.3 GPA for as-received condition, however, it decreased 24.6 GPa due to gamma heating, which was above the value of the specimen with same annealing effect without irradiation. Weight change of specimen with oxidation increased with annealing time, temperature and amount of dose 0.21-0.27 mR/h. Hardness change of the irradiated specimen followed by annealing was significantly dependent upon amount of dose of the specimen.