In this study, we have investigated the nanofabrication of asymmetric ferromagnetic ring arrays by capillary force lithography, which incorporates the essential feature of nanoimprint lithography. The capillary lithography technique enables the fabrication of large area magnetic nanostructures and makes it possible to systematically control the shape of magnetic nanostructures. We prepared various ferromagnetic Co ring arrays with various ring widths down to 100 nm. We investigated magnetization reversal of ferromagnetic nanoring arrays using the focused magneto-optical Kerr effects (FMOKE) and micromagnetic simulation. It was found that magnetization reversal could be controlled by varying the width and asymmetry in ferromagnetic nanoring structures.