Objective To analyze and explore the value of 3 T high resolution magnetic resonance vessel wall imaging for identifying the activity of Takayasu arteritis. Methods Twenty-six consecutive patients with Takayasu arteritis underwent 3.0 T high resolution MR vessel wall imaging on supraortic vessels (according to the classification of Lupi-Herrea , type Ⅰ and Ⅲ were included). Sixteen patients were in active phase and 10 in inactive phase based on the Kerr criteria. The MR vessel wall imaging appearances of Takayasu arteritis were compared between the active phase and inactive phase cases. Results Wall thickening was demonstrated in all involved arteries. There were statistically significant differences between active phase and inactive phase cases in MR appearances including multi-ring thickening of vessel wall (75/80 and 18/50), arterial inner wail enhancement (50/80 and 19/50), obscurity of perivascular fat (55/80 and 18/50,X =50.39,7.41,13.40,P<0.01). There was also a statistically significant difference in the thickness of carotid artery wall between the two groups [ (3.8±0.2) mm vs (2.5±0.8) mm]. Conclusion 3 T high resolution MR vessel wall imaging is valuable for identifying the activity of Takayasu arteritis. Key words: Takayasu arteritis; Magnetic resonance imaging