Abstract: Objective To assess the accuracy of 3D-slicer software in reconstructing data of intracranial aneurysmal with magnetic resonance angiography (MRA) and high resolution magnetic resonance imaging (HRMRI). Methods DICOM data of MRA and HRMRI of the inpatients who were diagnosed with unruptured intracranial aneurysms in the neurosurgery department of our hospital from January 2013 to October 2014 were collected and reconstructed by 3D-slicer software, then the results were compared with the gold standard digital subtraction angiography (DSA) to find out whether results of the two measurements had any differences. Results Of the 16 patients in our study, nine were males and seven were females with average age of 48.7 years (ranging from 16 to 72 years). There were no statistically significant difference in value of aneurysm height, aneurysm diameter and width of aneurysm neck between DSA and MRA (9.68±4.51) mm vs (9.65±4.55) mm, t=0.147, P=0.885; (14.39±6.71) mm vs (14.55±6.96) mm, t=-0.442, P=0.665; (3.70±1.15) mm vs (3.51±1.42) mm, t=0.908, P=0.378. Conclusion The reconstructive results with MRA data by 3D-slicer software is quite accurate and it is beneficial for aneurysm surgery.