Sulfur-doped C, films were prepared by simultaneous evaporation of C, powder and high-purity sublimed sulfur. The temperature-dependent conductivity was measured after the samples were annealed at 433K for 8h. The obvious semiconductive property has been confirmed in the temperature range of room temperature- -368 K. The activation energy decreases and the conductivity increases with an increase in the sulfur doping level. A transition of the electrical transport behavior has been found in the temperature ranging from 368K to 388K, which can be attributed to the variation of the charge-transfer between C60 molecules and sulfur clusters as a result of the structural change of the sulfur clusters.