The clinical manifestations of immune thrombocytopenia(ITP)are quite similar to the onset characteristics of hidden pathogen，which makes it possible to discuss the pathogenesis of this disease based on the theory of hidden pathogen.The authors believed that excessive pathogen is dominant，blood relieved by pathogenic heat and the stagnation of blood stasis are common in the acute stage of the disease；vital qi deficiency is dominant，including the syndrome of yin deficiency and hyperactivity of fire and the syndrome of deficient qi failing to control，in the chronic stage of the disease，which can serve as a guidance for the clinical treatment based on syndrome differentiation.