A new radiation-hard germano-silicate glass optical fiber with a pure silica glass buffer and a boron-doped silica glass inner cladding was fabricated for temperature sensor application based on the fiber Bragg grating (FBG) under --ray irradiation environment. The temperature dependences of optical attenuation at 1550.5 nm and Bragg reflection wavelength shift from 18 ℃ to 40 ℃ before the γ-ray irradiation were about 4.57×10^–4 dB/ ℃ and 5.48 pm/ ℃ , respectively. The radiation-induced optical attenuation at 1550.5 nm and the radiation-induced Bragg reflection wavelength shift under the γ-ray irradiation with the total dose of 22.85 kGy at 35 ℃ were about 0.03 dB/m and 0.12 nm, respectively, with the γ-ray irradiation sensitivity of 5.25×10^–3 pm/Gy. The temperature and the γ-ray irradiation dependence of optical attenuation at 1550.5 nm in the FBG written fiber with boron-doped silica glass inner cladding were about 6 times and 4 times lower than that in the FBG written fiber without boron-doped silica glass inner cladding under a temperature change from 18 ℃ to 40 ℃ and the γ-ray irradiation with the total dose of 22.85 kGy at 35 ℃, respectively. Furthermore, the effect of temperature increase on the Bragg reflection wavelength of the FBG written fiber with boron-doped silica inner cladding was much larger about 1000 times than that of the γ-ray irradiation. However, no influence on the reflection power of the Bragg wavelengths and the full width at half maximum (FWHM) bandwidth under temperature and the γ-ray irradiation change was found. Also, after the γ-ray irradiation with the dose of 22.85 kGy, no significant change in the refractive index was found but the residual stresses developed in the fiber were slightly relaxed or retained.