The processes of heat transfer in microparticles in the gas atmosphere due to kinetics of phase change (melting) under laser radiation have been numerically investigated. The temperature dependence of thermal and optical parameters, irradiative cooling and heat exchange with the gas atmosphere are considered. The dynamics of temperature distribution of particles of different sizes subject to melting has been determined. The dependences of the time of full melting on the properties of particles and on laser radiation have been obtained. This will help to choose the right regime of laser treatment in selective laser sintering.© (2010) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.