This study aimed to evaluate the effect of purgation therapy with Natrii sulfas, a therapy for stroke patients with constipation in the oriental medicine, on the ischemic brain damage of the rats. The ischemic brain damage was induced by the middle cerebral artery occlusion (MCAO), Natrii sulafas was administered once after the MCAO. After 48 hours, expressions of Bax, Bcl-2, c-Fos, and HSP72 on the brain tissues were observed by immunohistochemistrical methods or technique. Purgation therapy with Natrii sulfas attenuated the excess of Bax expression caused by the ischemic brain damage. It was significant statistically in the penumbra of cerebral cortex, but not in the caudate putamen, of the MCAO rats. Purgation therapy with Natrii sulfas did not attenuate the excess of Bcl-2 expression caused by the ischemic brain damage. Purgation therapy with Natrii sulfas did not attenuate the excess of c-Fos expression caused by the ischemic brain damage. Purgation therapy with Natrii sulfas attenuated the excess of HSP72 expression caused by the ischemic brain damage. It was significant statistically in the penumbra of cerebral cortex, but not in the caudate putamen, of the MCAO rats. These results suggest that purgation therapy with Natrii sulfas has a neuroprotective effect on the ischemic brain damage and an anti-apoptotic effect.