Solid state C-13 CP/MAS studies of poly(vinyl chloride) (PVC)-bis(2-ethylhexyl) phthalate (DOP) have been carried out to elucidate the dynamics of polymer-plasticizer interaction at the molecular level. C-13 NMR spectra, spin-lattice relaxation time T-1(C) and spin-spin relaxation time T-2(C) were obtained for various PVC-DOP samples. Line widths of >CH-Cl show a sharp increase due to the strong hydrogen-bonding interaction between the >C=O (ester) group of DOP and >CHCl of PVC with various concentrations of DOP. The spin-lattice relaxation time T-1(C) also confirms the presence of a strong interaction due to hydrogen bonding. The less mobile intermediate phase is mostly affected by the presence of plasticizer The spin-spin relaxation time T-2(C) shows that DOP,is a mixed type plasticizer showing the features of both molecular and structural type plasticization.