A simulated light oil consisting of model sulfur compounds of benzothiophene (BT), dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) and straight-run light diesel oil fractions as solvent was employed for desulfurization tests imitating silver-salt method for ionic liquids (ILs). Under the conditions of a nitrogen atmosphere, reaction temperature of 303 K, reaction time of 24 h, the effects of different alkylating agents and amount of agent on the sulfur removal were investigated in more details. The results showed that when ratio of bromoethane (CH3CH2Br) to sulfur is 80: 1 (mol/mol) and ratio of potassium tetrafluoroborate (KBF4) to sulfur 30: 1 (mol/mol), the desulfurization yield were 72.6%.