It is well known that intracranial pressure (ICP) and mean arterial pressure (MAP) are increased by laryngoscopy and endotracheal intubation during induction of general anesthesia, and It may be very dangerous in neurosurgical patients who had increased ICP. Therefore, this study was performed to know the range of ICP increase during induction of the conventional general anesthesia with intubation following thiopental and succinylcholine injections. Intracranial pressure and MAP were measured in 13patients who underwent cramotomy. All the patients were monitored cerebral epidural ICP and intra-arterial pressure pre-operatively. The results were as follow: 1. Intracranial pressure was increased of $7.1{pm}7.23mmHg$. 2. Arterial pressure was increased of $43.5{pm}25.46mmHg$. 3. Cerebral perfusion pressure was increased of $33.3{pm}27.53mmHg$. It is stressed that certain procedures are necessary to prevent from further increase of ICP due to induction of general anesthesia in patients with increased ICP.