The structure of the ctenidium and the labial pulp of the Black-lip pearl oyster, Pinctada margaritifera, was examined with corrosion casts and histological sections. The casts were made using the prepolymerization methyl methacrylate（MercoxCL-2R）containing 10% Mercox MA. Surfaces of the basal ciliated tracts of laminae at ctenidia and surface of the food groove were covered with the cilia. The food groove was formed by the ordinary filaments with the extended and deformed tip, and the primary filaments connecting close to the center of the supra-branchial chamber side. The inner and outer lamina connected with the inter-laminar connecting membrane at the junction region of the primary filaments, and exhibited the structure of "Heterorhabdic filibranch". However, the membrane did not spread out to the inter-laminar connecting vessel. The frontal surfaces of ordinary and primary filaments were covered with the frontal cilia, and the lateral sides of the filaments with the lateral cilia. The mucous cell was interspersed in the frontal surfaces of filaments.