Pictorial key to pupa of the genus Olenecamptus in Korea is provided. This study was carried out with pupa of five species in Korea: Olenecamptus formosanus Pic, 1914, Olenecamptus octopustulatus (Motschulsky, 1860), Olenecamptus clarus Pascoe, 1859, Olenecamptus cretaceus cretaceus Bates, 1873 and Olenecamptus subobliteratus Pic, 1923. The description of life cycle and host-plant of the genus Olenecamptus are also given.