In this experiment, etching was performed on the incisor enamel surfaces of 13 Albino rats, weighted about 130gm, with both 30% and 50% concentrations of the phosphoric, citric acids, and EDTA solution for 60 seconds. Immediately after extraction of the animal teeth, laboratory procedures for scanning electron microscopic observations were made and the author derived the following conclusions: 1. On the enamel surface treated with 30% and 50% phosphoric acids, all of the periphery, center of the enamel rods, and the enamel matrices were severely etched. 2. In the etched with 30% citric acid group, only the small part of the enamel rods were etched out. In case of 50% citric acid the periphery, center of enamel rods were partially or entirely etched, and the intermatrix spaces were widened. 3. In the 30% and 50% of the EDTA etched groups, the periphery of the enamel rods explicitely were etched, and the spaces between matrices were widened.