To summarize the clinical experience of professor Cao Yemin in the diagnosis and treatment of pediatric livid vasculitis, and to improve the clinical diagnosis and treatment ability of livid vasculitis. Lividuct vasculitis is a non-inflammatory, intradermal vascular obstructive skin disease characterized by recurrent painful ulcers, reticular lividuct, and satellite scars of porcelain white at the distal extremities of both lower limbs. It usually occurs in summer. The etiology of livid vasculitis is not clear. Current studies have shown that the pathogenic factors are hypercoagulable organism, fibrinolysis disorder and/or related to immune system diseases. According to the physiological and pathological characteristics of children, professor Cao identified the cause of the disease, that the disease position in the "collaterals", the characteristics of the disease is "deficiency, evil, blood stasis", according to the clinical manifestations, divided into acute attack, recovery and recovery period 2 stages, disease differentiation and syndrome differentiation combined. In the acute stage, clearing heat and cooling blood, and removing blood stasis with Ying were the treatment principles, and the prescription of cooling blood and Ying was added or subtraction. During the convalescence period, Fuzheng Qingjie prescription was added or subtracted by Fuzheng Qingjie prescription. In addition, Professor Cao is good at both internal and external treatment, and attaches great importance to emotional care, so as to achieve the purpose of after-treatment.