The authors experienced a case of a difficult decannulation in a 4 years old boy, in which case decannulation was possible 2 years later a tracheostomy. Some immunological phenomena could be considered in this case as though cancer can remiss spontaneously. During his aging process, such complications of tracheostomy as subglottic edema and perichondritis could become relatively less troublesome to breathing. And another reason for the successful decannulation is considered as the patient could be accustomed to breathing through natural air pathway be continual cannula corking training.