A fiber-optic surface plasmon resonance (SPR) sensor for temperature detection has been proposed by utilizing a thermosensitive liquid as the intermediate and combining with the fiber SPR structure. The sensing element of the sensor has been fabricated by packaging the fiber probe coated with a silver layer into a capillary filled with thermosensitive anhydrous ethanol. This packaging can protect the metal layer from oxidation and damage. Moreover, this proposed sensor achieves a sensitivity of 1.5745 nm/°C, which is much higher than that of the traditional fiber SPR sensor according to the comparative experiments.