목적: Recently we can open the dura mater of the skull base widely for removing the intradural tumor by endoscopic endonasal approach, because the various methods for skull base reconstruction have been developed.Using nasoseptal pedicle flap is one of the most popular methods for the reconstruction. Posterior septal nasal artery is the branch of sphenopalatine artery, and feeds blood to the nasoseptal flap. We need to identify the location of posterior septal nasal arteries in each surgical case and avoid to damage them when we make the pedicle flap. Intraoperative ultrasound doppler can be useful for keeping the feeding arteries and making the flap successfully. 방법:In each operative case from April 2013 to January 2014, we counted the branches of posterior septal nasal artery with intraoperative ultrasound doppler , and identified the location of them. 결과:There were 26 concecutive cases during this period. We perceived the pulsation of posterior septal nasal artery in 18 cases. There was only one pulsation site in each one of 15 cases, and two pulsation sites in 3 cases.Main location of the pulsation was at inferomedial of the middle nasal concha. We will demonstrate how the pedicle flap is made in the operative video. 결론:We counted the branches of posterior septal nasal artery with intraoperative ultrasound doppler , and identified the location of them in our operative cases. We can keep the feeding arteries of the nasoseptal pedicle flap and making it successfully by this method.