Oil shale as it occurs in nature consists of solid organic material interspersed in a shale formation. This organic matter can be converted by means of heat to lower molecular weight liquid products. Various retorting processes are used for this conversion of organic material to shale oil. The Bureau of Mines, as part of the Synthetic Liquid Fuels Program, has established an Oil-Shale Research and Development Laboratory at Laramie, Wyoming to study retorting and refining processes. One phase of this study is an investigation of the composition of shale oil. The present paper reports results an material in the naphtha boiling range.