Abstract: Objective: To investigate the value of β2-microglobuin(β2-MG) in the evaluation of tubulointerstitial injury in IgA nephropathy(IgAN).Methods: The levels of β2-MG in blood and urine and scores of tubulointerstitial injury in 201 IgAN patients were investigated using the immunoturbidimetric method and Katafuchi semi-quantitative standard,respectively.Results: With the aggravation of tubulointerstitial injury,the levels of β2-MG in blood and urine increased significantly.The levels of β2-MG in blood and urine were positive correlation with the tubulointerstitial injury(P<0.01).When the level of serum β2-MG was normal(<2.2 mg/L),the tubulointerstitial lesion was found in 95.6% of patients,which included the moderate tubulointerstitial lesion in 13.2% of patients,and the level of β2-MG in urine was not correlation with the tubulointertitial lesion(P>0.05).Conclusions: The abnormal increasing of the serum level of β2-MG has great value in evaluating the tubulointerstitial injury of IgA nephropathy.