The structure of integumentary epidermis is studied in the bastard halibut, Paralichthys olivaceus based on the light and transmission electron microscope. Epidermal layer consists of supporting cells, unicellular glands and accessory cells. The supporting cells were classified into superficial cell, intermediated cell and basal cell. Superficial cell of epidermal layer is squamous or cuboidal and the surface is covered with numerous microridges. The supporting cells are connected to another cell with membrane interdigitations and desmosmes. And tonofilaments are developed in the cortical cytoplasm. Gland cells are classified into mucous cell and club cell. By the histochemical studies of the epidermal secretions the mucous materials are identified as neutral polysaccharides. Club cell has numerous vacuoles and microfilaments in the cytoplasm. Also chloride cells are observed in the epidermis, it cytoplasm is occupied numerous mitochondria.