The microvascular architecture of all kinds of lingual papillae in the Japanese monkey was investigated on plastic corrosion casts and epithelium-separated specimens under a scanning electron microscope. Three kinds of the filiform papillae were observed; the circularly-arranged papillae with a small papilla in the center on the lingual apex, a simple large conical papilla with a bilateral pair of spines on the lingual body and the aggregated filiform papillae on the top of an epithelial projection on the lingual radix. Five to eight capillary loops were arranged in a circle of the above filiform papillae on the lingual apex. Arterioles ascended in the filiform center on the lingual body to form an intrapapillary network in the shape of a large cone, from which capillary loops were observed only on the top surface of the papilla. Capillary loops arising from the subepithelial capillary network in the epithelial projection were distributed to each filiform papilla on the lingual radix. Globular fungiform papilla on the lingual apex were supplied by capillary loops radiating from the intrapapillary capillary network. Cylindrical fungiform papillae on the lingual body were supplied by capillary loops only on the top surface of each fungiform papilla without any loop formation on the lateral surface. Four vallate papillae, a medial and lateral pair, were supplied by arterioles ascending in the papillary center to form an intrapapillary capillary network, from which capillary loops were sent off on the top surface of the papilla and formed a network in the lateral surface. Each foliate papilla was supplied by an arteriole passing through each papillary center along the long axis and 5 or 6 capillary loops from the arteriole on the frontal section. Every lingual papilla was supplied by a characteristic microvascular pattern, which correlated closely with the location of the papillae and areas reflecting the regional role of the tongue movement, especially in the filiform and fungiform papillae.