In this paper from a practical point of view, the viscosity behavior is studied for three different suspensions; UV inks, aqueous lattices, and electrorheological fluids. (1)After the printing process, the UV inks are rapidly cured old exposure to UV irradiation. To evaluate the sensitivity, the viscosity changes in curing are measured by the use of an oscillating plate rheometer newly-developed. (2)The flow of flocculated suspensions is generally pseudoplastics, because the floc structure are progressively broken down with increasing shear rate. When the polymer chains do not have strong affinity for the particle surfaces, the absorption-desorption of polymer occurs reversibly by thermal energy. (3)The electrorheological(ER) fluids are rapidly and reversibly converted between Newtonian fluids Bingham bodies on the application or removal of electric fields. Although the primary method of formulating excellent ER fluides is high dielectric particles, the surface polarization plays an essential role. The surface modification has great potential in the ER technology.