Isothermal (gas + liquid) equilibrium (GLE) data at T = 308.15 K and p = 122.60 kPa are reported for the absorption of dilute SO(2) in various aqueous poly-ethylene glycol 400 (PEG) solutions, in which SO(2) partial pressures are in the range of (0.9 to 92) Pa. Measurements are carried out by a saturation method using a glass absorption apparatus, which was controlled at constant temperatures by a thermostatic circulation bath with a Beckmann thermometer. The GLE data were obtained with uncertainties within 0.02 K for temperature, 0.1 kPa for total pressures, 3% for SO(2) concentration in the gas phase, and 0.6% for SO(2) concentration in the liquid phase. The measurements show that the solubility of dilute SO(2) in the system of (PEG (1) + water (2)) increases with increasing PEG concentration in the mass fraction range of w(1) = (0.40 to 1.00), and the solubility of SO(2) in the system of (PEG (1) + water (2)) presents an extreme minimum at the mass fraction of w(1) = 0.40 of 190 mg L(-1) when SO(2) in the gas phase is designed at 4,Phi(SO2) = 5 . 10(-4). The peculiarity of this work is 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 the solutions containing PEG. (C) 2011 Elsevier Ltd. All rights reserved.