The effect of an applied electric field (E-field) on the dynamics of polystyrene (PS) in tetrahydrofuran (THF) was studied by quasielastic light scattering. The concentration of the PS/THF solution was varied from very dilute to semidilute, and the E-field was applied up to 7.14 kV/cm. In the dilute to semidilute regime, the relaxation rate of PS increases sharply with the increase of applied E-field. The dilute regime was overlooked in previous studies. However, going beyond the semidilute to concentrated regime, the applied E-field has only a diminishing effect on the dynamics of PS/THF solution. The observed electric field induced effect is found to be closely related to the polarization current of the polymer solution.