The secondary structure of plasma proteins those were denatured by heating or mixing with alkaline halide were discussed. The α-helical structure changed to β-structure by forming KBr pellet, and changed to disordered structure by heat denaturation in phosphate buffer solution (pH 7.4). Those data were made clear by amide III band. The integrated intensity ratio of amide II band to amide I band depended on the α-helix content in denatured albumin. The hydrogen-deuterium exchange reaction rate of denatured albumin was larger than the rate of native it. The spectra of organic materials on nonmetallic inorganic substrates were theoretically discussed by the reflection absorption spectroscopy. The spectrum calculated was in good agreement with the experimental spectrum. The monochlonal antibody immobilized on glass plate was semi-quantitatively evaluated by this method. The spectra of esters in micelle solution were studied to discuss the existing state of esters solubilized into sodium decanoate micelle. The acetates may be solubilized into the surface polar layer of the micelle, and the polar environment around the solubilized acetates may induce the conformational changes in acetates. The spectral method had been discussed for measurement of the non-spherical and cohesive particles existed in atmosphere.