Abstract： Objective　To evaluate the clinical value of EBCT in the diagnosis of aorto-arteritis (Takayasu′s disease) involving ascending aorta and aortic valve. Methods　EBCT was carried out by Imatron 150-XP system using contrast enhancement (non-ionic contrast media 300 mg I/ml) in 25 patients with aorto-arteritis during the period from Apr, 1996 to Sept, 1999. Among the series of 25 cases, ascending aorta and aortic valve were involved in 17 patients (14 females, 3 males). The age ranged from 11 to 58 years with mean age of (34±13) years. ECG gated single slice mode (SSM) was performed with slice thickness of 3 mm and scanning time of 0.1 s; continues volume scanning (CVS) was performed with slice thickness of 3 mm and scanning time of 0.1 s. The EBCT features of ascending aorta and aortic valve were analyzed in the 17 cases with aorto-arteritis. Four patients of these cases had severe aortic insufficiency and underwent operation of aortic valve replacement. Two years later, circumvalve leak occurred in two of these four cases and relived with aortic valve replacement again. Results　EBCT image showed the thickening of ascending aortic wall in all 17 cases, and all the lesions extended to the aortic valve. EBCT features of wall-thickening appeared as a concentric wall thickening or double density ring in 10 patients with active disease and low-density ring in 7 patients with inactive disease. 11 of these patients showed ascending aortic dilation with aortic valve regurgitation. Conclusion　Wall-thickening of aorta was the basic feature in EBCT images. According to our study, aorto-arteritis (Takayasu′s disease) involving ascending aorta can also involve aortic valve and resulte in aortic valve regurgitation. Active stage of aorto-arteritis was the contraindication of surgery therapy. EBCT was an important method for the diagnosis of aorto-arteritis (Takayasu′s arteritis) and the stage of aorto-arteritis can be reflected by EBCT.