The reactions of poly(4-vinylbiphenylj (denoted as PVB) polymers and biphenyl molecules with solvated electrons in the 2-methyltetrahydrofuran(MTHFj solvent have been studied at 100-120 K by electron-pulse radiolysis. The formation of PVB polymer anions as well as biphenyl anions was observed by the electron-pulse irradiation of the MTHF-PVB(or biphenyl) solution. The anions are formed by two processes; a rapid formation during the pulse irradiation (<20 ns) and a slow formation after the pulse irradiation. The slow formation is due to a diffusion-controlled reaction between solutes, such as PVB and biphenyl, and solvated electrons. It was found that the reaction efficiency, expressed in monomer unit, of PVB polymers is 1/27 of that of biphenyl molecules. The reaction radius for the electron capture reaction of PVB polymers is estimated as 200-370 A, which is much larger than the gyration radius (107 A) of polymer coils in MTHF solution.