Electric field effects on photoinduced electron-transfer processes have been examined in a polymer film for methylene-linked compounds of phenanthrene and NN-dimethylaniline, based on the measurements of the field effects on fluorescence spectra. Both intra- and intermolecular electron-transfer processes are enhanced by an electric field (F), depending on the methylene chain length, and LE fluorescence emitted from the locally excited state of phenanthrene chromophore is quenched by F. Exciplex fluorescence is also influenced by F. The magnitude of the change in molecular polarizability following fluorescence process has been determined from the Stark shift both for LE fluorescence and for exciplex fluorescence.