A lattice-Boltzmann method (LBM) was used for simulation of the 2D binary coalescence of droplets. The main subject of our interests is the influence of the droplet size and the interfacial tension on binary coalescence time (BCT). The BCT of two free particles as well as the case when one of the particles is deposited on the surface is considered. The results of calculations are in good agreement with experimental data presented in other papers. (C) 2011 Elsevier Ltd. All rights reserved.