Objective    To compare the clinical efficacy and side-effects of high dosage methylprednisolone combined with plasmapheresis or only with high dosage methylprednisolone treatment in patients with anti-neutrophil cytoplasmic antibodies (ANCA) associated vasculitis (AAV).   Methods    Forty-seven patients with clinicopathologically diagnosed as ANCA-associated vasculitis kidney damage, whose clinical manifestations were also consistent with rapidly progressive glomerulonephritis syndrome, were treated with high dosage methylprednisolone and plasmapheresis (PE group, n=22) or only with high dosage methylprednisolone (MP group, n=25). Patients received these two regimes were comparable in general conditions and clinicopathological parameters for the activity and severity of renal damage.    Results    At the 6 month, the serum level of ANCA were both lower significantly than before (P＜0.05), and the PE group had the advantage to the MP group (P=0.028). The renal function was improved both in the two groups, and the serum creatinine of PE group was significantly lower than that in the MP group (P=0.043). The BVAS scores were both significantly decreased in the two groups (P＜0.05), and the scores were lower in the PE group than that in the MP group (P＜0.05). Both the serum albumin and hemoglobin levels in the two groups were significantly increased after treatment (P＜0.05), while the differences before and after treatment  of the two levels between the two groups both had no significant difference (P＞0.05). Three patients developed to end stage renal failure in each group during the follow-up period. The incidences of gastrointestinal symptoms (12.0％ and 9.1％ in MP and PE group, respectively) and infectious complications (28.0％ and 22.7％ in MP and PE group, respectively) were similar between two groups.    Conclusions    Both the high dosage methylprednisolone combined with plasmapheresis treatment and the high dosage methylprednisolone treatment have significant effects on patients with ANCA associated vasculitis, while the high dosage methylprednisolone combined with plasmapheresis treatment may be more effective in decreasing serum level of ANCA and improving renal function .