Abstract: The commercial trial of a nontoxic sulfur transfer additive SFTS-1 for reducing sulfur dioxide emissions in FCC flue gas developed by China University of Petroleum (East China) was carried out at Petrochemical Plant of Shengli Oilfield Co. Ltd. SINOPEC and it was introduced in this paper. Trial results showed that compared with base case under similar feedstock properties and operation parameters, when said additive occupied 4% of the catalyst inventory and stabilized at this level for 6 d, the SO2 content in regeneration flue gas dropped from 1 300 mg/m3 to 245 mg/m3, keeping a sulfur removal rate of above 80%; then without adding additive for 11 d, the sulfur removal rate still could be remained at 69%. At the same time, no significant negative effect on product distributions and product properties was observed during the trial.