In the sequence of carbon tetrachloride hepatotoxicity, increased serum levels of a number of enzymes have been demonstrated in experimental animals. These observations, therefore, have served to help in detecting hepatic injury. The serological influence of chlorpromazine (CPZ) and iproniazid on the acute $CCl_4$ poisoning was executed in this investigation taking use of 6 albino rabbits (around 2 kg b.w.) in each group. By measuring of blood sugar level (Nelson-Somogyi method), S-GOT and S-GPT activities (Reitman-Frankel method), the pharmacological effects of the drugs was evaluated setting pretreated groups against the control. The results obtained were summarized as follows: 1. The intramuscular injection of $CCl_4$ led to increase the blood sugar level in first 3 hours and, after that, to decrease reasonably. But CPZ-pretreated group showed a tendency of increasing in compare with the control, and iproniazid-pretreated group inhibited evidently. 2. In S-GOT activity, the increased level was induced by $CCl_4$ in control. And CPZ-pretreated group showed a increased level until first day and decreased rapidly. But this property inhibited inhibited significantly by pretreating with iproniazid. 3. Although a single dose of $CCl_4$ increased the S-GPT activity, the more increasing trend was observed in CPZ-pretreated group. But these tendencies depressed remarkably in the iproniazid-pretreated group. It seemed to be attributed not to defend the $CCl_4$ toxicity but to be suppressed the enzyme systems in the liver by iproniazid that the blood sugar level and serum transaminase activities was decreased significantly in pretreating with iproniazid.