Abstract: Objective To investigate the clinicopathological features and differential diagnosis of mucinous tubular and spindle cell carcinoma（MTSCC） of kidney. Methods Two cases of MTSCC of kidney were studied with clinical data,histopathologic,and immunohistochemical staining and review the related literatures. Results The age of patients was 66 and 54 years old(one male and one female）respectively.One case was found by physicial examination and the other because of anemia.The cut surface of the tumor was solid with a yellow to gray in color with no cysts.Microscopical detection showed that the tumors were composed of variable proportions of tubular and spindle cell areas with prominent mucinous or myxoid stroma；some tumor cells were uniformly cuboidal with ovoid to round nuclei and eosinophilic or clear cytoplasm,cuboidal cells are arranged in tubules and cords;the other tumor cells showed spindle,which were arranged in the fascicular pattern,resembling smooth muscle tumors.One cases showed spindle cell predominance and the other showed tubular predominance.Immunostaining showed that tumors were positive for CK(AE1/AE3),EMA,vimentin，and one tumor focally express Syn,but negative for desmin, CgA,S－100,SMA,CD117,CD34,CD10,HMB45,p53,ER and PR.Both tumors had low proliferative index of less than 1%.Follow-up in 2 patients（7 and 10 months）showed no recurrence. Conclusion MTSCC of kidney is a rarely low malignant renal cell carcinoma,it should be differentiated from other renal tumors.