Cerebral vascular territories are related to the clinical progression and outcome of ischemic stroke. The vascular territory map (VTM) helps to understand stroke pathophysiology and potentially the clinical prognosis. A VTM can be generated from the bolus arrival time map. However, previous methods require initial seed points to be chosen manually, and the region inferior to the circle of Willis is not included. In this paper, we propose a method to automatically generate a map of the whole cerebral vascular territory from CT perfusion imaging. We applied the proposed method to 19 cases of ischemic stroke to generate VTM for each case.Clinical Relevance- The proposed map may improve the interpretation of the physiological status of collateral flow for ischemic stroke, and aid in treatment decision making.