A novel macroinitiator of poly(ethylene oxide) (PEO) with a 4-hydroxy-2,2,6,6-tetramethylpiperidinyloxy (HTEMPO) end group (PEOHTM) was prepared by the photochemical reaction of a tertiary amine end group of PEO with benzophenone (BP in the presence of HTEMPO. Potassium 2-dimethylaminoethoxide was used to initiate the ring-opening polymerization of ethylene oxide first, then the dimethylamine end group of PEO constituted the charge-transfer complex with BP under UV irradiation, and finally ternary amine methylene and diphenyl methanol radicals were formed. The former reacted with HTEMPO to form the desired product. PEOHTM can initiate the polymerization of styrene by a ＇living" radical mechanism. The molecular weight of the PS block increased with the polymerization time, and the molecular weight distribution (M-w/M-n) was less than 1.5, even though the molecular weight of the former was as high as 2 x 10(5). The DSC measurement of the copolymer confirmed that the T-g of the PS block was 106 degrees C, which was 6 to 7 degrees C higher than that of the PS prepared by the common radical method.