This study tries to develop an explicit and phenomenological model to describe transport properties of penetrants through nanocomposite membranes. The model development procedure was conducted regarding experimental observations. Poly(Ether Block Amid), PEBAX (grade 1657), and SiO2 nanopartides were applied to fabricate the neat and the nanocomposite membranes. Permeability, solubility and diffusivity of four permanent gases (CO2, H-2, N-2 and CH4) were measured through the fabricated membranes at temperature range of (298-338 K), and a fixed transmembrane pressure (TMP) of 2 bar. The proposed model was developed based on the solution-diffusion theory, to calculate solubility, diffusivity and permeability of the penetrants through the nanocomposite membranes. The Van Amerongen and Van Krevelen relations were applied to estimate solution and diffusion coefficients of the penetrants through the neat membrane regarding the physical properties of penetrants and glass transition temperature of the polymer. Then, solution and diffusion coefficients through the nanocomposite membranes were correlated to those of the neat membrane and structural properties of the nanocomposite membranes. The results showed that the presented model in this study can efficiently calculate solubility, diffusivity and then permeability of the penetrants through the fabricated nanocomposite membranes (e.g. the calculated values and the experimental data have a correlation coefficient, R-2, higher than 0.95, 0.97, and 0.96 for solubility, diffusivity and permeability, respectively). (C) 2016 Elsevier B.V. All rights reserved.