Abstract: By reacting of benzene with Chlorine in the Presence of Sb₂S₃-I₂ as a Catalyst,We have Obtained paradichlorobenzene under mild conditions in high yields and good quality. The experiments indicate that the used catalyst has fair activities on the reaction of selective catalytic chlorination of benzene. In the fraction of dichlorobenzene the proportion of paradichlorobenzene is equal to 88% or so. The main factors which affect the reaction are reaction temperature, the chlorine-flow speed, the amount of the catalyst used and stirring efficiency. Experiments show that the optimum reaction conditions are:(1) the molar ratio of chlorine to benzene:2.8:1, (2) chlorination temperature:20～60℃, and (3) amounts of Sb₂S₃ and I₂:1% and 0.2% of benzene weight, respectively.