For spectrochemical analysis by solution technique, various electrodes-orous cup electrode, rotating disk electrode, suck-up electrode and others-are being used.Among these, rotating disk electrode seems preferable, for it is simple and economical in treating a large number of samples. Fundamental of this technique, however, does not seem to have been fully studied. With solutions of copper alloys, the effect of particulars of rotating disk electrode and solution on the analysis is studied and the following conclusion is drawn.1.Machining accuracy of the electrode influences the accuracy of analysis.2.Coefficient of correlation between porosity of the disk and spectral intensity is negative.3.Excitation with sulphuric acid is less in spectral intensity than with aqua regia but has good reproducibility.4.As to internal standard elements, bismuth, cobalt, indium and molybdenum are found satisfactory for analysis of copper alloys.