The present report is the first for which this newly-formed Commission has been responsible. In view of this fact, and in view of the still exploratory nature of many investigations in spectrophotometry, as well as the need for the highest measure of individuality in the attack of the not simple problems involved, it would be premature to propose, simple though it might be to do so, any far reaching plans for co-operative schemes of investigation. These undoubtedly will play a part in the later work of the Commission, but what appears to be needed now is a closer definition of the aims of spectrophotometry, and at least a reference to the many branches of the subject where investigation is needed. The present report attempts to deal with these topics in three successive sections, concerned in turn with the unique property of spectrophotometric measures, the fields of application of spectrophotometry, and recent developments in a still incomplete and difficult technique.