We study the sliding contact between a rubber block and a sinusoidal surface.In order to elucidate the effects of the wavelength and amplitude of a sinusoidal surface on the friction coefficient,we performed a systematic experiment by tuning the wavelength and amplitude of the sinusoidal surface.We also performed a finite element analysis to reproduce the experimental results.We found that the fluctuation of the friction coefficient accommodates the wavelength and amplitude of the sinusoidal surfaces.We also observed that the localized deformation occurs at the leading edge of the rubber block,depending on the wavelength and amplitude of a sinusoidal surface.