Background Relapses occur frequently in patients with lupus nephritis.Renal biopsy is the gold standard for assessing renal activity and hence guiding the treatment.Whether repeat renal biopsy is helpful during flares of lupus nephritis remains inconclusive.In the present study,we retrospectively reviewed the patients with lupus nephritis who had more than one renal biopsy with the hope to find the clinical value of repeat biopsy.Methods Patients who had a diagnosis of lupus nephritis and two or more renal biopsies were selected from the database of the patient pathology registration at this renal division.Renal biopsy was evaluated according to the International Society of Nephrology/Renal Pathology Society (ISN/RPS) classification of lupus nephritis.The pathological patterns and treatment regimens were analyzed after a repeat biopsy.Results We identified 44 systemic lupus erythematosus patients with serial renal biopsies.In total,there were 94 renal biopsies.Overall,the pathological transition occurred in 64％ instances according to the ISN/RPS class.When the transition was analyzed according to proliferative,membranous or mix lesions,it showed different profile:35％ in patients with proliferative lesion,23.5％ patients with mix lesions,100％ in patients with pure membranous lesion.The pathological transition could not be predicted by any clinical characteristics.After the repeat renal biopsy,34％ of patients had a change in their treatment regimens.Conclusions The pathological conversion was very prevalent in patients with lupus nephritis.However,the transitions became less prevalent when they were analyzed according to pure membranous,proliferative,and mix lesion.Repeat biopsy might be helpful to avoid unnecessary increased immunosuppression therapy.