Phlegm of Traditional Chinese Medicine(TCM) includes the narrow definition and broad definition spurtlm,whicll is vety different from the sputum of modem medicine.With the development Of modern medicine,we try to reveal the scientinc character of phlegm of TCM.Mucin participates broad definition sputum of TCM,and is Similar in disposition and pathopoiesis.So we think mucin is one ofmaterial foundation Ofthe sputum of TCM.