Liquid refractive index changes when temperature changes. According to this theory, a novel optical fiber optical temperature sensor based on surface plasmon resonance (SPR) is presented in this paper. And the theory of the SPR probe testing the change of environmental temperature is analyzed. The structure of SPR probe is optimized in order to measure the temperature of liquid with high refractive index and enlarge the measurement range, The characteristic curve of SPR spectrum changing with temperature is obtained by using a optical fiber SPR temperature testing system. A real-time double-parameter measure method, based on resonance wavelength λspr and the lowest light intensity reflectivity Rmin, is also presented. The experimental results show that this sensing system features simple structure, all light transmitted by fiber, and easiness to realize long distance measurement.