The initiation of fabric smoldering combustion is known to be in fluenced by a heat source and the properties of the fabrics. In order to understand what is most critical to the smoldering ignition of fabric, it is important to develop a predictive model. In the present study, a mathematical model has been devel oped based on the heat transfer mechanism involved in the heating of cotton ducks and upholstery fabrics by vertically and horizontally placed cylindrical car tridge heaters. The reaction kinetics of the cotton pyrolysis and char combustion are considered in the model. The effect of temperature on the material properties and the surface heat transfer coefficient is also taken into account. The integral method is used in solving the governing heat transfer equations. The model pre diction of the temperature history of the fabrics and the time to ignition agrees quite well with the experimental results. The theoretical ignition temperature of fabrics may be defined as the material temperature at which the char combustion becomes dominant. Thus, the ignition temperatures of cotton ducks of different basis weight or treated to various ion content levels can differ.