A 69-year-old man was admitted to our hospital because of left primary lung cancer. As tumor invasion to the descending artery was suspected, preoperative endovascular ultrasonography was performed. Part of the wall lacked respiratory movement. However, the wall of the descending artery was visualized as three layers, i.e., hyper-, hypo- and hyperechoic layers by sonography, so tumor invasion to the descending artery was diagnosed as negative. Although inflammatory tumor adhesion to the descending artery was found, left upper lobectomy was safely performed. Endovascular ultrasonography was considered to be useful in marking an accurate diagnosis of tumor invasion to the descending artery.