Selective laser sintering/melting (SLS/SLM) is an additive manufacturing process that uses laser energy to sinter/melt powder particles together to construct solid structures. Materials modeling of microstructure evolution during such processes can be of great importance, especially for process control and optimization. In literature, most modeling efforts have been focused on the microstructure evolution during SLM, while few attempts have been made to study the microstructure evolution as a result of SLS. In this study, a phase-field (PF) based SLS model is developed to predict the evolving of microstructure in the solid-state SLS process. The effects of laser power intensity and scanning speed on microstructure evolution are investigated. The feasibility and capability of modeling in a large scale are demonstrated. The modeling results are validated by experimental findings in terms of the neck size between adjacent particles. This PF based SLS model is found to be capable of predicting the neck growth for various metallic materials including 316 L stainless steel, titanium, and nickel. (C) 2018 Elsevier B.V. All rights reserved.