Abstract: Based on yin fire theory proposed by LI Gao, discusses the etiology, pathogenesis and clinical treatment thoughts of immune thrombocytopenia(ITP). The pathogenesis of ITP is deficiency of both spleen and kidney, and yin fire burns blood collaterals. The main treatment principle is to fortify spleen, supplement kidney and subdue fire, and the prescription should be modified Buzhong Yiqi tang.