This study aimed to explore the incidence of Anti-neutrophil cytoplasmic antibody (ANCA）-associated vasculitis (AAV) progression and its association with adverse consequences. It will enroll approximately 500 AAV patients in Hunan province of China and follow-up for at least 5 years. Demographic characteristics, clinical and laboratory data will be collected at baseline and every follow-up. The principal clinical outcomes of the study consist of end stage renal disease (ESRD) and death.