This study was carried out to investigate the early morphologic effects of halothane anesthesia to the rat liver cells. Albino rats were moderately anesthesized with halo-thane for I hour, and sacrificed immediately, at 4 hours, and at 12 hours after anesthesia respectively. And the livers were extracted out and observed by the electron microscope. The results obtained were summarized as follow: Immediately after anesthesia, marked dilatation of rough and smooth ER, large ampitude swelling of mitochondria, and shedding and disorganization of ribosomes were found similar degenerative changes were noted at 4 hours after anesthesia and these changes were returned to normal limits after 12 hours except dilation of lumina of ER. Autophagosomes were increased immediately after anesthesia, and were changed to autophagolysosomes and residual body at later time. Golgi complex was proliferated with increased primary lysosome formation from 4 hours to 12 hours after anesthesia. The results suggested that halothane could induce degenerative changes of rat liver cells, which accelerated autophagocytosis at later time.