Electrohydrodynamics of a dilute solution of rigid macromolecules was experimentally studied in a continuation of previous theoretical work. We used poly(γ-benzyl-L-glutamate), having 4 different molecular weights ranging from 15,000 to 236,000, dissolved in m-cresol. Poly(γ-benzyl-L-glutamate) solutions were subjected to combinations of simple shear flow field and uniform electric field perpendicular to the shear direction. Transient birefringence and extinction angle were simultaneously measured using the phase-modulated birefringence method. Steady state results were compared with the theoretical prediction from previous worts and rotational diffusivity and permanent dipole strength of PBLG were obtained from multiple parameter fitting. Consequently, the optical state of PBLG solution could be explained to a certain extent by the dimensionless field parameters established in the previous theory.