Transition metal-mediated atom transfer radical polymerization(ATRP) is a ‘‘living’’/controlled radical polymerization. Recently, there has been widely increasing interest in reducing the high costs of catalyst separation and post-polymerization purification in ATRP. In this work, trolamine was found to significantly enhance the catalytical performance of Cu Br/N,N,N0,N0-tetrakis(2-pyridylmethyl) ethylenediamine(Cu Br/TPEN) and Cu Br/tris[2-(dimethylamino) ethylamine](Cu Br/Me6TREN). With the addition of 25-fold molar amount of trolamine relative to Cu Br, the catalyst loadings of Cu Br/TPEN and Cu Br/Me6 TREN were dramatically reduced from a catalyst-to-initiator ratio of 1 to 0.01 and 0.05,respectively. The polymerizations of methyl acrylate, methyl methacrylate and styrene still showed first-order kinetics in the presence of trolamine and produced poly(methyl acrylate), poly(methyl methacrylate) and polystyrene with molecular weights close to theoretical values and low polydispersities. These results indicate that trolamine is a highly effective and versatile promoter for ATRP and is promising for potential industrial application. Transition metal-mediated atom transfer radical polymerization (ATRP) is a ’living’ / controlled radical polymerization. Recently, there has been widely seen increasing interest in reducing the high costs of catalyst separation and post-polymerization purification in ATRP. In this work , trolamine was found to significantly enhance the catalytical performance of Cu Br / N, N, N0- tetrakis (2-pyridylmethyl) ethylenediamine (Cu Br / TPEN) and Cu Br / tris [2- (dimethylamino) ethylamine] Br / Me6 TREN). With the addition of 25-fold molar amount of trolamine relative to Cu Br, the catalyst loadings of Cu Br / TPEN and Cu Br / Me6 TREN were dramatically reduced from a catalyst-to-initiator ratio of 1 to 0.01 and 0.05, respectively. The polymerizations of methyl acrylate, methyl methacrylate and styrene still showed first-order kinetics in the presence of trolamine and produced poly (methyl acrylate), poly (methyl methacrylate) and polystyrene with molecular weights close to the theoretical values ​​and low polydispe rsities. These results indicate that trolamine is a highly effective and versatile promoter for ATRP and is promising for potential industrial application.