Abstract: IgA vasculitis（IgAV） is the most common vasculitis in children，in which long-term prognosis is mostly dependent upon the severity of renal involvement. The risk factors of developing to IgAV nephritis（IgAVN） are age above 10 years at onset，mail，abdominal pain and recurrence of vasculitis. 97% of IgAVN developed renal symptoms within 6 months after purpura presentation. Haematuria，mostly microscopic，company with or without microproteinuria is the most common resentation of IgAVN in children. The pathology of IgAVN is characterized by intrarenal，mesangial or vascular deposits of IgA and mesangial cells and mesangial matrix proliferation，which iasimilar with IgA nephropathy. The important risk factors of poor kidney out come were IgAVN presented with nephrotic syndrome or kidney in sufficiency at onset. However some IgAVN patients who pressent with mild initial symptoms also eventually developed CKD. The patients with the ISKDC class Ⅳ and Ⅴ are more likely to progress to ESRD. Control of nephrotic range proteinuria is beneficial to long-term prognosis. Improved treatment strategies and detection of IgAVN patients at risk of CKD at an early stage are necessary.