It has been shown that thin-walled hyperelastic tubes could bulge under inflation.In this paper we investigate the possibility of bulging for thin-walled tubes composed of plastoelastic/viscoelastic materials.A general bifurcation condition is derived by near-critical post-bifurcation analysis, which can degenerate into an existing special one for hyperelastic tubes.It is demonstrated that the linearly elastic and plastoelastic tubes can bulge under inflation, but viscoelastic tubes cannot bulge unless the value of inflating pressure is just equal to the one of the critical pressure for the corresponding elastic tubes.