Antennal surface structure of the Japanese tusser, Antheraea yamamai was observed by scanning electron microscope. The antennae of male and female were bipectinate with scape, pedicel and 33--37 flagellar segments. There were two pairs of equal long branch on eacli flagellar segment of male (Fig.1), but a pair of longer and a pair of shorter on female's (Fig.2).Seven types of sensillum, namely sensillum trichodeum, sensillum cheaticum, sensillum coeloconicum, sensillum campaniformlum, sensillum styloconicum, Bohm's bristle and sensillum squamiformium wer found on the antenna both of male and female. The sensillum trichodeum could be subdivided into long and short according to the shape and surface substructure. The long sensillum trichodeum had a diameter of 4.8μm at its base. It was reratively stright and slightly curved at the tip (Fig.3). The short sensillum trichodeum was 2.5--3.6 μm in diameter at the base. It was shorter, strongly bend down near its base and run parallel with the surface of the antenna (Fig.4). The surface of long and short sensilla trichodea were covered with annular ridges (Fig.5).