The present invention provides a drug capable of preventing or treating diabetic nephropathy.The present invention relates to a prophylactic and/or therapeutic drug for diabetic nephropathy, comprising a RARγ agonist as an active ingredient. The present invention also provides a prophylactic and/or therapeutic drug for renal anemia； a drug inhibiting the expression of type IV collagen in mesangial cells； a drug inhibiting the expression of BMP4 in mesangial cells； and a drug inhibiting fibrosis in the renal tubulointerstitium.
