Abstract: From 1945 to 1949 clay-mineral studies in Belgium were connected with the Comité Belge pour l'Etude des Argiles. In 1947 this group organized the C. I. P. E. A., which in turn helped to form active national groups of clay workers. Clay-mineral research is now pursued in five laboratories in Belgium. Projects in Brussels include industrial problems, study of reactions of silicates and the oxides of Al, Ca, and Mg; quantitative determinations by x-ray spectrometry; and the use of a differential thermobalance and electron microscopy. Basic clay-mineral problems involving agriculture are being studied at Heverlee, where investigations include studies of fixation of iron on kaolinites and examination of the topography of kaolinite minerals attacked by different reagents. A group at Tervuren has been concerned with formation, deferrization, and determination of oxides by D. T. A. The Laboratoire National des Silicates at Mons is investigating creep phenomena in refractories. The activities of the Ghent group are described in a separate paper.