Abstract： Based on HUANG Yuanyu's theory of "The circumfluence of qi"， this paper discusses and analyzes the experience of Prof．HONG Qinguo in treating chronic renal failure with Wendan tang．It introduces the theoretical origin of "The circumfluence of qi"，the Chinese medicine pathogenesis of chronic renal failure and the meaning of Wendan tang．It is pointed out that Prof．HONG classifies chronic renal failure as shenlao in Chinese medicine，and the pathogenesis of shenlao is based on the decline of the spleen and kidney，which can be summarized as "yang deficiency，water-cold，earth-damp， and wood-depression"．By using Wendan tang，the central qi pivot can be restored，the four manifestations maintained and the clear and the turbid also restored．