The corrosion resin-casts and the tissue preparations (Azan staining) of the digestive diverticula of the Japanese short-neck clam, Ruditapes philippinarum were observed. The digestive diverticula surrounded the stomach on sides except the dorsal side. The orifices of the multiple ducts located at three embayments of the stomach. Internal wall of the duct was covered from the orifice to the apex with the cilium. Each tubule extended to the end of the duct. The tubule had the darkly staining cell at the crypt.