Isothermal gas-liquid equilibrium (GLE) data have been measured for the system diethylene glycol (DEG) (1) + water (2) + SO(2) (3) + N, (4) at 298.15 K and 123.15 kPa and SO(2) partial pressures in the range of (0.7 to 100) Pa. Measurements were carried Out by l saturation method using a glass absorption apparatus, which was controlled Lit constant temperatures by a thermostatic circulation bath with a Beckmann thermometer. The GLE compositions were obtained with relative uncertainities within +/- 0.6 % for SO(2) concentration in the liquid phase and +/- 3.5 % for SO(2) mole fraction in the gas phase. The measurement showed that the system DEG (1) + water (2) in the mass fraction range of w(1) = (0.60 to 1.00) decreased the solubility of SO(2) and the system DEG (1) + water (2) in the mass fraction range of w(1) = (0.00 to 0.60) increased the Solubility of SO(2). Compared With our previous work (Zhang, J. B.; Wei, X. H.; et al. J. Chem. Eng. Dato 2008, 53, 2372-2374; Zhang, J. B.; Wei, X. H.; et al. J. Chem. Eng. Data 2009, DOI: 10.021/je900392e), the Solubility of SO(2) in pure DEG is 259 mg-L(-1) when SO(2) Volume fraction in the gas phase is Phi(3) = 5.10(-4), which is higher than in pure ethylene glycol (EG, 128 mg.L(-1)) and lower than in pure poly(ethylene glycol) 400 (PEG 400, 1330 mg.L(-1)). The results Of this work can be used to provide important GLE data for the design and operation of the absorption and desorption process in flue gas desulfurization (FGD) with potential industrial application of Various PEG aqueous Solutions.