Objective To discuss possible mechanism of kidney-protecting effect of Danzhi Jiangtang Capsule（ DZJT capsule） for diabetic rats. Methods Of 55 rats

9 were assigned into normal group

the other 46 rats were fed with high-fat diet for four weeks

then intraperitoneally injected streptozocin（ STZ） 35 mg / kg once to make model diabetes. Forty-one successful models were randomized into model group（ n = 11）

pioglitazone group（ n = 10）

low-dose DZJT capsule group（ n = 10） and high-dose DZJT capsule group（ n = 10）. The high-dose and the lowdose DZJT capsule group were respectively given DZJT capsule 1. 08 g /（ kg·d）

0. 54 g /（ kg·d） as gavage. The pioglitazone group was given pioglitazone 10 mg /（ kg·d） by gavage

while the model group and the normal group were given normal saline 5 ml /（ kg·d） by gavage

lasting for eight weeks. Then measured blood glucose and blood fat

and collected kidney tissue to analyze pathology and osteopontin（ OPN）. Results Kidney damaged seriously in the model group

but in the high-dose DZJT capsule group

no significant change was found

with the structure of kidney tubules and glomeruli legible. Pathologic changes of the high-dose DZJT capsule group were less than the lowdose group. The level of blood glucose

blood fat and OPN in the model group increased more obviously than that of the normal group（ P < 0. 01）. In the high-dose and the low-dose DZJT capsule group and pioglitazone group

the levels of blood glucose

blood fat and OPN decreased more obviously than in the model group（ P < 0. 05 or P <0. 01）. Conclusion DZJT capsule may markedly improve renal lesions of diabetic rats

effectively reduce blood glucose and blood fat. These effects may be due to DZJT capsule reducing the overexpression OPN in nephridial tissue.