A mathematic model of carbonyl sulfide (COS) removal at low temperature with fouling of catalyst has been developed based on experimental results. Kinetic studies were conducted in a fixed bed reactor under atmospheric pressure and at low temperature (40-70 degrees C). Experimental results of breakthrough curves were used to obtain kinetic parameters accounting for axial dispersion, external and internal mass-transfer resistances as well as the sulphur deposition on inner-face of catalyst. Initial bulk porosity of particle (epsilon(P0)), deactivation coefficient (alpha), sulfide deposition coefficient (beta) were used to quantify the behavior of COS removal at different operating conditions. Adsorption heat of H2O and activation energy of COS removal was 21.5 and 62.4 kJ/mol respectively. The effects of flow rate, COS inlet concentration, temperature and relative humidity(RH) were analyzed, and it was found that relative humidity carried a heavier weight than temperature on epsilon(P0), alpha, beta within our experimental conditions. The model agreed well with the experimental breakthrough curves and satisfactorily predicted the fixed-bed reactor performance, and this model can be used as a reliable tool for process design and scaling-up of similar system. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.