The syndromes of liver manifestations are widely used to guide the disease differentiation and treatment in modern medicine，which has achieved good therapeutic effects.The theory of liver being firm-characterized zang organ is a high generalization of liver physiology，which is of great significance for the diagnosis，prevention，and treatment of liver manifestations.By discussing the genesis，this paper deepens the connotation of the theory of liver being firm-characterized zang organ.Furthermore，according to this theory，this paper discusses the common clinical symptoms and causes of liver diseases and puts forward the treatment methods of emolliating，pacifying，draining，and clearing the liver，enriching the theory and treatment methods of liver manifestations in TCM.