Knowledge of transport and thermodynamic properties in polymersolvent system at elevated pressures and temperatures is important for many applications. The pressure decay method is a technique that can be used for measuring solubility and diffusivity in polymer-solvent systems. This technique has been used to obtain preliminary ternary data on polyvinyl acetate with toluene and nitrogen as a solvent and gas. Also the GCLF-EoS has been used to analyze the ternary system.