The present invention discloses a belly-type breath auxiliary device comprising body, belt assembly and breath monitoring unit. The body includes a box. The box positions the breath monitoring unit, and connects two end of the belt assembly by elastic members. The breath monitoring unit has movement detecting unit, signal processing unit and warning unit. The movement detecting unit produces a signal when detecting the third connecting member moves to a specific position, and the signal processing unit determines the user finishing one time of effective breath by the signal. The warning unit acts to remind the user keeping his belly-type breath when the movement detecting unit does not detect the third connecting member moving to the specific position within a specific time.
