The histochemical, cytochemical, and immunocytochemical investigations were conducted to find out the cellulase activity in the accessory glands of the digestive system of the oriental land snail Nesiohelix samarangae under the LM, SEM, and TEM. The cellulase activity was shown in the epithelium of th digestive gland by labelling with the immunogold (protein-A gold) particles. The epithelial cells showing the cellulase activity were Type 1 and Type 3 cells out of five types of the epithelial cells of the digestive gland. None of epithelial cells of the mucus gland and the salivary gland and the salivary gland were not labeled with the immunogold particles.