Objective To observe and analyze the accuracy of perfusion imaging and CT scan in determining preoperative grading of gliomas. Methods 76 cases of patients with gliomas who were treated in our hospital between January 2009 and December 2012 were retrospectively analyzed. All underwent perfusion scan and CT enhanced scan. Based on the imaging data of the two kinds of diagnostic methods, preoperative grading of perfusion imaging was performed with reference to cerebral blood volume (CBV), cerebral blood flow (CBF), cerebrovascular permeability surface (PS) and relative cerebral blood volume (rCBV) values. Results The postoperative pathological results were taken as the standard. In terms of perfusion imaging, the values of CBF, PS, CBV and rCBV of lesion areas in the two different grade of groups were greater than the corresponding values of the contralateral normal areas (P＜0.05). The perfusion parameters of high grade group were significantly greater than the corresponding values of low grade group (P ＜0.05). The determination accuracy rates of perfusion imaging in low and high grade group (90.24%,91.43%) were significantly higher than those of CT enhanced scan (73.17%, 71.43%) (P＜0.05). Conclusion The accuracy rate of perfusion imaging in determining preoperative grading of gliomas is higher than that of CT enhanced scan. It is an effective method for preoperative diagnosis of gliomas