Abstract： Objective To study the application of bypass and revascularizatiou in the treatment of complex intracranial aneurysms.Method From Nov 2002 to Mar 2008,twenty-four patients with complex intracranial aneurysms underwent aneurysmectomy followed by primary reanastomosis,aneurysm trapping followed by saphenous vein or superficial temporal artery bypass procedures.Results Four aneurysms were excised with primary reanastomosis,16 of 24 aneurysms were trapped followed by saphenous vein high-flow bypass,and 4 were excised followed by superficial temporal artery low-flow bypass.At discharge,twenty-two out of the 24 patients had a Glasgow Outcome Scale score of 4 to 5,one patient was severe disability and one was dead.Conclusions Bypass or revascularization is a sound and reliable procedure in the treatment of complex intracranial aneurysms.The M2 segment of middle cerebral artery is the optimal recipient to accept bypass vessel.