Abstract: Objective: To improve the recognition of renal disorders in multiple myeloma(MM).Methods: The kidney biopsy of 17 cases of MM were analyzed retrospectively.Results: The pathologic types included chronic interstitial nephritis(n=13),mesangial proliferative lesion(n=11),cast nephropathy(n=9),renal amyloidosis(n=5),glomerulus sclerosis(n=4)and renal mesenchyme artery vessels and angiohyalinosis(n=4).Renal failure was significantly higher(P=0.002 3)in patients with cast nephropathy(n=9)than in those with non-cast nephropathy(n=8).Free light chain was detected in the serum of 88.2% patients and in the urine of 58.8% patients,with λ chain as the dominant type.Conclusions: The most frequent clinical syndrome of MM with renal lesion is renal insufficiency.Cast nephropathy is the most frequent pathological type.The clinical manifestations and pathological changes of MM patients with renal lesion and cast nephropathy have some common features.