Objective To study the microsurgical skills in the management of splitting neck of aneurysm of supraclinoid part of internal carotid artery ( ICA ).Methods 765 patients with intracranial aneurysms had been operated between December 1997 and August 2011.Among 288 cases of aneurysms of supraclinoid part of ICA,the necks of aneurysms in 8 cases were splitted from the trunks of ICA during operation.In the first 4 cases the ICAs had to be occluded.In the last 4 cases the ruptured holes were clipped with autogenous dura maters and straight angled ring aneurysm clips.Results In the first 4 cases with occluded ICA,2 patients died (GOS:1 score) and 2 had serious neurological disfunction(GOS:3scores).The last 4 cases with protected ICA,all patients have good results (GOS:5 scores ).Conclusions During the surgery of aneurysm in the supraclinoid part of ICA,if the neck is splitted from ICA,instead of ligation the ICA,we should clip the rupture hole with autogenous dura mater and aneurysm clip and protect ICA in order to avoid serious consequences.