Objective:To summarize the clinical curative effect and experiences in the microsurgical treatment for middle cerebral artery bifurcation aneurysms(MbifAs). Methods:The clinical data and operation process of 28 patients underwent microsurgery surgi-cal treatment for middle cerebral artery bifurcation aneurysm were retrospectively analyzed. Results:Thirty MbifAs were found in 28 patients including 5 patients with complicated intracranial hematoma. Preoperative computed tomography angiography or digital sub-traction angiography was performed to evaluate the form and size of aneurysms and its relationship with bifurcate of blood vessels. Microsurgery was carefully designed for all patients. All patients were followed up for 6 months to 1 year. According to glasgow outcome scale of 28 patients,22 were recovered well,4 moderately disabled,1 severely disabled,1 vegetatively survived. Conclusion:Early surgery is necessary for middle cerebral artery bifurcation aneurysms. Accurate preoperative imaging analysis and evaluation,appropri-ate surgical approach,skilled operation skills to clip aneurysm are the keys to improve the prognosis of surgery.