A new method of simulating temperature programmed desorption (TPD) spectra from porous surface using the Monte Carlo (MC) technique is presented. We introduce so called single pore model (SPM) to describe porous system. Simulations on heterogeneous lattices with particular boundary conditions reflecting a pore geometry are proposed. The technique allows to obtain qualitative and quantitative illustration of influence of porosity on TPD spectra. Examples of simulated TPD curves for model pores are presented. (C) 2003 Elsevier B.V. All rights reserved.