The effect of hepatic injury produced by CCL, was studied on rats receiving a low protein-high carbohydrate (7% casein), standard protein (20% casein) and a high protein diet (30% casein). The rats fed low protein diet are resistant to CCl$_4$ in its effects on the liver as judged by histology, serum enzymes(guanase, ALT) and the content of hepatic protein. On the other hand, the pretreatment of hydrocortisone before injection of CCl$_4$ to the rats fed a standard diet, slightly decreased both serum ALT and guanase activities. In the pretreatment of actinomycin D, the liver and serum guanase activities were significantly decreased. It indicates that the cause of increasing serum guanase is based on the alteration of membrane permeability and the result of accelerated enzyme synthesis in liver cells of CCl$_4$ intoxicated rats.