The Polyester fibers are one of the most important synthetic fibers, which have supreme physical and chemical properties and have been used in wide variety of applications. Though flame resistance of these fibers is low, and in contact with flame they would shrink, melt, and drop. Moreover, if contact with flame continues, polyester fabric would burn and melting drops would be generated, which in apparel application of these fibers it is quite an important and noticeable issue mostly because melting drops would led to more intense wounds. Furthermore, these fibers are reluctant to absorb moisture and easily generate electrostatic charge in normal atmosphere, which if moisture absorbance increases this problem would be solved. Polymer-clay nanocomposite is a new branch of polymeric materials which has better thermal and mechanical properties in comparison with polymer itself. Mentioned nanocomposites have different structures which are used in different applications and purposes. For the first time, in this research nanoclay applied on the fabric using finishing techniques and burning behavior of fabrics have been changed by these techniques which resulted in prohibiting melting drops and more char formation during burn.