In this study, uniform dumbbell-shaped non-spherical particles are produced by seeded polymerization, and the electro-rheological (ER) properties are compared to those of spherical-shaped particles after surface coating with functionalized multiwall carbon nanotubes (f-MWCNTs). The non-spherical particles formed linear chains under an applied electric field. The yield stress of the non-spherical particles is five-times as high as that of the spherical particles. The enhanced ER properties of the dumbbell-shaped non-spherical particles are attributed to the discrete dipole moments, which are found to depend on the morphology.