The early diagnosis and effective treatment of brain abscess pose a difficult clinical problem. With the advent of computed tomography , however, it appears that motality due to intracranial abscess has significantly diminished. 54 cases of intracranial pyogenic abscess are presented. Etiologic factors and computed tomographic findings are analyzed and following result are obtained. 1. The common etiologic factors are otitis media, post operation, and head trauma, in orderoffrequency. 2. The most common initial computed tomographic findings of brain abscess is ring contrast enhancement with surrounding brain edema. 3. The most characteristic computed tomographic finding of ring contrast enhancement is smooth thin walied ring contrast enhancement. 4. Most of thick irregular ring contrast enhancement are abscess associated with cyanotic heart disease or post operation. 5. The most common finding of epidural and subdural empyema is crescentic readioluscent area with thin wall contrast enhancement without surrounding brain edema in convexity of brain.