Two continuous cell lines, NIAS-MaBr-92 and NIAS-MaBr-93, were obtained from larval hemocytes of the cabbage armyworm, Mamestra brassicae. The cells grew in suspended state. Spherical cells were predominant, although there were spindle shaped and irregular shaped cells. The chromosome numbers of the cell lines varied very much with the mode of 100 of 120. The population doubling times of these cell lines were about 36hr. The cells could grow in media free of serum and lacking sterols, fatty acids and protein. The cell lines consumed ammonia and produced glutamine when cultured in MM medium. The cells could be stored at -100°C for more than two year, and at 5°C for two months. The cells were sensitive to Autographa californica nuclear polyhedrosis virus and Chilo iridescent virus.