Under isothermal quasi-static stretching the phasetransition of a superelastic NiTi tube involves the formation(during loading) and vanishing(in unloading) of a high strain(martensite) domain.The two events are accompanied by arapid stress drop/rise due to the formation/vanishing of domain fronts.From a thermodynamic point of view,both areinstability phenomena that occur once the system reaches itscritical state.This paper investigates the stability of a shrinking cylindrical domain in a tube configuration during unloading.The energetics and thermodynamic driving force of thecylindrical domain are quantified by using an elastic inclusion model.It is demonstrated that the two domain fronts exhibit strong interaction when they come close to each other,which brings a peak in the total energy and a sign changein the thermodynamic driving force.It is proved that suchdomain front interaction plays an important role in controlling the stability of the domain and in the occurrence of stressjumps during domain vanishing.It is also shown that the process is governed by two nondimensional length scales(thenormalized tube length and normalized wall-thickness) andthat the length scale dependence of the critical domain lengthand stress jump for the domain vanishing can be quantifiedby the elastic inclusion model. Under isothermal quasi-static stretching the phase transition of a superelastic NiTi tube involves the formation (during loading) and vanishing (in unloading) of a high strain (martensite) domain. The two events are accompanied by arapid stress drop / rise due to the formation / vanishing of domain fronts. Flash a thermodynamic point of view, both are instability phenomena that occur once the system reaches its critical state. This paper investigates the stability of a shrinking cylindrical domain in a tube configuration during unloading. The energetics and thermodynamic driving force of thecylindrical domain are quantified by using an elastic inclusion model. It is that the two domain fronts exhibit strong interaction when they come close to each other, which brings a peak in the total energy and a sign change in the thermodynamic driving force. suchdomain front interaction plays an important role in controlling the stability of the domain and in the occurrence of stressjum ps during domain vanishing. It is also shown in the process is governed by two nondimensional length scales (thenormalized tube length and normalized wall-thickness) andthat the length scale dependence of the critical domain lengthand stress jump for the domain vanishing can be quantified by the elastic inclusion model