Abstract: The effects of temperature on the evolution and self-deflection of bright photovoltaic spatial solitons in photovoltaic photorefractive media are investigated with numerical method by taking account of diffusion effect. It is found that the bright solitary beam appears in stable state, large periodic compression and expansion state, or breakdown state when the crystal temperature changes. The results show that the bending distance of the bright solitary beam centre increases with temperature rise, then reaches its maximum value at a specific temperature, and after that, decreases as temperature continuously rises; it approaches zero at low and high temperature ranges. The maximum deflection value and its corresponding specific temperature increase as the intensity of incident solitary wave increases. The self-deflection process of the bright solitary beam is further studied with the perturbation technique, and the results indicate that the values agree with those obtained from the numerical method.