The prevent invention discloses a structure of thermal resistive layer and the method of forming the same. The thermal resistive structures, formed on a plastic substrate, comprises a porous layer, formed on said plastic substrate, including a plurality of oxides of hollow structure, and a buffer layer, formed on said porous layer, wherein said porous layer can protect said plastic substrate from damage caused by the heat generated during manufacturing process. With the structure and method disclosed above, making a thin film transistor and forming electronic devices on the plastic substrate in the technology of Low Temperature PolySilicon, i.e. LTPS, without changing any parameters is easy to carry out.