Glycogen synthetase and phosphorylase activity was studied in the rabbit cornea electron histochemically. Glycogen synthetase and phosphorylase were located in the cytoplasmic matrices of the corneal epithelium, but glycogen synthetase was found to be mainly in the superficial half of the epithelium, and phosphorylase mainly in the deep layer. Since the cells in the deep layer of the corneal epithelium contain rich cytoplasmic organelles which have carbohydrate metabolism from glycogen or glucose through the Embden-Meyerhof pathway to the TCA cycle, glycogen synthesized in the superficial half of the corneal epithelium by glycogen synthetase may be transferred to the deep layer of the epithelium and broken down by phosphorylase. Phosphorylase in the superficial half of the corneal epithelium may break down overproduced glycogen so as to avoid the deposition of a large number of glycogen particles for maintenance of corneal transparency.