Objective To approach the hemodynamic changes of ischemic cerebrovascular diseases and its influencing factors.Methods With the 40 patients' results of digital subtraction angiography(DSA) and computed tomography perfusion ilnaging(CTPI), the relationships between the degree/location of cerebrovascular stenosis and the hemodynamic changes were analyzed to guide the formation of therapeutic regimens.Results There was no correlation between the different stages of CTPI and different degrees of stenosis of extracerebral (r=0.08, P=0.57) and intracerebral (r=0.007,P=0.951) artery stenosises; The different gradings of collateral circulation had statistically significant effect with the stage of CTPI, P<0.05; and the different types of collateral circulation had no statistically significant effect with the stage of CTPI, P>0.05.Conclusions To combine the DSA and CTPI, we can evaluate the cerebrovascular morphous and the hemodynamic changes comprehensively and provide informations for formalating the therapeutic regimens.