To study the effect and mechanism of the treatment for reinforcing Kidney and activating blood circulation (RKAB) in treating chronic pyelonephritis. Using RKAB combined with western drugs to treat 41 patients with chronic pyelonephritis and controlled with 30 patients treated with western drugs only. Changes of kidney morphology

renal function were observed

and the long-term efficacy of treatment was pursued. The short-term effective rate in the treated group and the control group was 90. 24% (37/41) and 86. 67% (26/30) respectively

with no significant difference between them (P>0. 05). The long-term effective rate in the two groups was 70.73% (29/41) and 30.00% (9/30) respectively with significant difference (P<0. 01). Moreover

the occurrence of morphological change of kidney and renal dysfunction in the treated group was later than that in the control group (P<0. 01). RKAB treatment could raise the long-term effect in treating chronic pyelonephritis

alleviate/ block the morphological change of kidney and retard the progressing of renal dysfunction.