The influence of temperature on ordinary hard bubbles and their corresponding hard stripe domains in epitaxial garnet bubble films was investigated experimentally, A critical temperature T0, which is related to the parameters of bubble films, was found. When the testing temperature T0, the VBL chains in hard domain walls are not changed after temperature increasing and then decreasing. When T>T0, however, the VBL chains disappear, so that all of hard domains become soft. When VBLs in walls are compressed, the harder the domain, the lower its softening temperature. During softening, the way of VBL disappearance is a sudden break down of the whole chain.