Poly (vinyl chloride) (PVC) nanocomposite have been prepared via solution technique. The nanocomposite structure based on the used modifier type and content was characterized with (XRD), (TEM) and (FTIR) spectroscopy. The results indicate the interaction of PVC into the clay layers giving an exfoliated PVC nanocomposites. FTIR data of the composites did not show any remarkable change in PVC.  The influence of the modifier content (i.e. 1, 2, 3, 4, 5, and 6 wt %) and type on the PVC was tested through physico-mechanical properties and thermal stability. The study demonstrated improved mechanical properties and thermal stability for the PVC/ carboxylated salts (3 wt %) composites compared with those of octadecyl amine (ODA) at the same loading. PVC/clay-ODA composite had worse thermal stability than that of unfilled PVC. Incorporation adipate acid salt (3%) results in a significant improvement of the thermal stability of PVC at 800^oC.