Based on the principle of Fresnel reflection and the optical time-domain reflectometry (OTDR) techniques, a quasi-distributed optical fiber temperature sensor which can achieve accurate temperature measurement is presented. The sensor head is made of two face-to-face single-mode optical fibers whose end surfaces have been polished. The gap betwen two fibers is filled with a temperature-sensitivity material. The temperature variation causes the refractive index of the filling material to change, and then the intensity of Fresnel reflection will be changed. A sensing scheme with three sensor heads in series is investigated in experiment. The slight changes in Fresnel reflection intensity are detected by OTDR, with which the temperature sensing characteristics are studied. The experimental results show that the Fresnel reflectivity increases monotonically when the temperature varies from -30 ℃ to 80 ℃. The sensor heads have good repeatability and low insertion loss.