Objective: To explore effect of the anti-infective part of Filifolium sibiricum(FS) on pyelonephritis. Method: Pyelonephritis model was established by unilateral ureteral obstruction and Escherichia coli injection into the bladder. The rats were divided into 6 groups:normal group(sham group)

model group

three dose groups of anti-infective part of FS (403.2

201.6

100.8 mg·kg-1)and positive control group (Cefixime capsules

36.87 mg·kg-1).Serum creatinine(Scr)

ureanitrogen(BUN)

albumin(Alb)and urine protein was monitored at different time point.ELISA was used to examine the content of circulating immune complex. The activity of interleukin-2(IL-2) was measured. Renal biopsy was performed to study the pathology changes. Result: There was no difference in Scr and BUN between FS groups and the model group. Compared with the model group

the left kidney coefficient increased in high dose group of FS. The activity of IL-2 was significantly enhanced in the FS groups(P<0.05). The optical microscopy outcome showed FS. anti-infective part could improve kidney pathological changes. Conclusion: FS had the effect of anti-inflammatory

furthermore FS could reduce glomerular inflammation and improve renal function

and had some therapeutic effects on pyelonephritis.