The three-month-old child’s ear is so smelly, there may be otitis externa, otitis externa eczema, otitis media and so on. 1 otitis externa: infants and young children with low immunity, improper parental care may lead to otitis externa, easily induced purulent infections, pus material, it can cause odor, may also be accompanied by symptoms of congestion and swelling of the external auditory canal. 2. Eczema of the external auditory canal: allergic factors lead to allergic reaction inflammation of the external auditory canal and auricular skin, because of the oozing of fluid from the external auditory canal, sometimes secondary to bacterial infections, the ear will have a foul odor. 3. otitis media: purulent otitis media, inflammation of the middle ear caused by bacterial infection, not only pus discharge from the ear, accompanied by a foul odor, accompanied by hearing loss and other symptoms, in severe cases, it can invade the skull, inducing meningitis and other intracranial complications. A three-month-old child’s ear is smelly, and should be examined and treated in a timely manner to avoid delays in diagnosis and treatment.