In this review, we describe the recent progress in the synthesis of responsive micro/nanogels and their swelling properties, with specific focus on the shear viscosity and the scaling relationship of stimuli-responsive micro/nanogel systems. We highlight the recent progress in the scaling models that provide important information on the swelling and rheological properties of responsive micro/nanogels, which are especially relevant in the applications of these soft nanostructures. Future perspectives on the applications of soft nanostructures are outlined and discussed.