Abstract: Anti-neutrophil cytoplasmic antibody(ANCA) associated small-vessel vasculitis has a high mortality rate. Particularly, patients with renal injury diagnosed by ANCA associated small-vessel vasculitis(AAV) are at high risk of progresses to end-stage renal disease(ESRD). In addition to glucocorticoids and immunosuppressants, plasma exchange is an essential treatment for ANCA-associated small-vessel vasculitis by removing of pathogenic substances in patients' plasma rapidly in order to improve the prognosis of the disease. However, it is still controversial of the use of plasma exchange for induction treatment of AAV. In this study, we analyzed the efficacy and safety of plasma exchange in the treatment of ANCA-associated small vasculitis. The Results approved that plasma exchange might be beneficial to reduce dialysis dependence in severe patients in a short period of time. But previous researches failed to determine whether plasma exchange was able to reduce creatinine level. Most prospective studies have suggested that plasma exchange was useless of improving patients'survival, while retrospective studies did not reach the agreement.