An experimental study was made on the dynamic theory of piston-ring lubrication, which was introduced in the 1st report. The apparatus used in this investigation had a stationary piston and a moving cylinder, the speed of which could be accelerated to 2000 r.p.m., and a constant or varied load was applied to the piston-ring by means of a rubber tire, which was pushed out by the compressed fluid. With the speed, load, temperature, and the phase of the varied load being changed, a frictional force of the piston-ring is measured by an electronic device which consisted of an elastic diaphragm, movable anode tube and oscillograph, These experimental results gave a good agreement both qualitatively and quantitatively with the theoretical value.