Chlorosilane-functionalized starch particles were prepared and adopted as a dry-based potential stimuli-responsive electrorheological (ER) material under an applied electric field. This ER fluid, prepared by dispersing the chlorosilane-functionalized starch particles in silicone oil, is considered to be a smart and intelligent material because the state of fluid changes from liquid-like to solid-like very quickly and reversibly under applied external electric fields. The ER behavior of the chain formation was examined using optical microscopy, while flow curves and dynamic moduli were investigated using a rotational rheometer with a Couette geometry under applied electric field strengths. The fluid exhibited typical ER characteristics of shear-dependent yield stress as a function of electric filed strength with a slope of 2.0, following a polarization model. It was also found that its ER performance was well correlated with the fluid's dielectric characteristics through Cole-Cole plot.