Chronic Pyelonephritis(CPN) is a common urinary tract infection in clinical practice， which has complicated and changing clinical manifestation. Profess Li Shunmin holds the idea that CPN can be categorized as qi strangury or overstrain strangury in Chinese medicine， which is a symptom of less evil and more deficiency. The treatment should be based on Zhang Zhongjing’s idea that “if the spleen functions well， then the evil will be kept out during four seasons” and Li Donghuan’s “the inner damage of spleen is the origin of many diseases”. Qidi Wushen decoction is therefore invented to treat CPN based on the principles of treating spleen and kidney，which has remarkable curative effect.