Objectives：To analyze the relationship between treatment and prognosis of unruptured intracranial aneurysms（UIAs）. Methods：Clinical data of 81 patients with 101 UIAs in the neurosurgery department of the First Affiliated of Chongqing Medical University from June 2006 to December 2009（mean follow-up time of 10.2 months） were retrospectively analyzed. Patients were treared by 3 methods：（1）surgical clipping，19 patients with 19 UIAs；（2）coil embolization，11 patients with 12 UIAs；（3）conservative obser－vation，53 patients with 70 UIAs. Fifty-eight patients with 70 UIAs were followed radiologically including 14 UIAs in clipping group，7 UIAs in coil embolized group and 49 UIAs in conservative observation group. Risk factors and relationship between treatment and prognosis of UIAs were analyzed. Results：Patients in clipping group all resumed their daily lives；2 patients in embolization group had slight disability；5 patients died，4 patients had moderate disability and 1 patient had mild disability in observation group；there was no significant difference among three groups（P=0.125）. Based on radiological follow-up，UIAs were mainly medium and small types（less than 10 mm）；14 UIAs in clipping group were clipped completely；1 UIA in coil embolized group was partially embolized；in conservative observation group，1 UIA had enlarged neck，2 UIAs had enlarged body and 5 UIAs ruptured（the size of all ruptured UIAs was less than 5 mm）；there was no significant difference among three groups（P=0.274）. Conclusions：UIAs are mainly medium and small types and the size of ruptured UIAs is often less than 5 mm. Treatment of UIAs still needs clarification. With the development of radi－ological technology，more and more small UIAs are certain to be detected，which will bring a new challenge for neurologist in clinical settings.