The change in the orientational order of ferroelectric liquid crystal molecules during the bending of the plastic cell substrate was studied with a polarizing optical microscope and birefringence data. The optic axis of neighboring striped domains gets widen while optic axis of one striped domain rotates more than that of the adjacent one does as a radius of curvature of the substrate gets shortened. Also the width of each stripe is increased and the liquid crystals in each domain orients more coherently. By the measurements of birefringence for the obliquely incident light, the liquid crystal molecules are found to rotate to the surface normal direction, too.