In this study, polyoxyethylene(POE) nonionic surfactants were used in order to enhance the solubilization of sulfur compounds contained in the crude oil and the solubilized sulfur contents in the aqueous surfactant solutions were measured by X-ray sulfur spectrometer. The most hydrophobic surfactant among used during this study showed the maximum solubilization capacity for the sulfur compounds in the crude oil and the solubilization of sulfur compounds was founds to be increased with temperature and to be abruptly increased at above 1wt% surfactant solutions. It was found that Tergitol series surfactants showed higher solubilizing capacity then Neodol series surfactants presumably due to the disruption of the regular packing in the hydrocarbon region of the surfactant aggregates. The addition of a cosurfactant such as alcohol and/or an electrolyte increased the solubilization of sulfur compounds in the crude oil. It was found that partitioning phenomena were shown to be significant with an hydrophobic surfactant at high temperature and the growth of sulfur reducing microorganisms was not greatly affected by the addition of nonionic surfactants.