In this dissertation work, subwavelength optical metamaterial structures were investigated for control of light transmission, absorption, and antireflection coating. These metamaterial structures are gold apertures for enhanced light transmission, gold subwavelength gratings for antireflection, and metal-insulator-metal structures for perfect light absorption. Gold apertures with star shapes on glass transmit light via excitation of surface plasmon wave, which is extraordinary transmission. It was found that the transmittance spectra depend on the period and the shape of the apertures. Gold subwavelength grating structure metamaterials exhibit dielectric property in one direction and metallic property in the other direction, functioning as polarization-selective antireflection coating. Metal-insulator-metal structure blocks light transmission and reflection is minimized at the resonance wavelength of the structure. Thus, this structure efficiently absorbs light and functions as a perfect light absorber. If top layer is disordered, the top layer plays a role as combination of resonating elements with various resonance wavelengths. As a result, metal-insulator-metal structure with disordered pattern renders wideband absorption property.