1) A rapid qualitative and semi-quantitative analytical procedure for gall stones by infrared absorption spectra was established, and bands for the chief components of the gall stone, cholesterol, bilirubin calcium, and calcium carbonate were clarified. 2) The component of the gall stone, formed artificially in a rabbit by the injection of serum, was found to be a protein and such a gall stone was found in a few cases of human specimen. 3) The calcium carbonate found in gall stones came in two types, argonite and calcite. 4) This procedure was found to be advantageous when employed in a clinical laboratory.