The Ti/4H-SiC Schottky barrier diodes(SBDs) were irradiated at room temperature with 60Co gamma-ray source, 1MeV electrons and neutrons, and 0V and -30 V bias voltage were applied to the diodes during gamma-ray and electron radiation. The meaurement results show that -30 V radiation bias voltage has no influence on the radiation effect of the diodes. After 1 Mrad(Si) gamma-ray and 1×1013 n/cm2neutron radiation respectively, the Schottky barrier height of the diodes basically remain the same values. After an electron dose of 3.43×1014 e/cm2, Schottky barrier height of the diodes slightly decreased, which was caused by ionizing damage of high energy electron, and recovered completely after annealing at room temperture. After gamma-ray and electron radiation, the reverse current of Ti/4H-SiC SBD had no obviously degration. The on-state resistance of the diodes increased after electron and neutron radiaiton.