In this paper, crosslinking process and thermo-mechanical properties of epoxy materials containing diglycidyl ether bisphenol-A (DGEBA) as the epoxy resin and JEFFAMINE (R) D-230 polyoxypropylenediamine as the hardener have been studied using molecular dynamics simulation. An algorithm to create the crosslinked epoxy has been developed, and the crosslinking process is monitored. The simulation results disclose the effectiveness of the using annealing in the crosslinking process to achieve higher crosslinking densities within shorter reaction radiuses while producing more desirable conformation. The evolution of the complex network of cured epoxy is studied by radial distribution function (RDF). The important properties of the epoxy material such as glass transition temperature (T-g), the coefficient of thermal expansion (CTE), and elastic constants are calculated. Furthermore, the variation of the properties through the evolution process is considered, and the improvement of them is captured. The results obtained from our simulation are in good agreement with the experimental results, revealing the strength of molecular dynamics to predict the material properties. Crown Copyright (C) 2015 Published by Elsevier Ltd. All rights reserved.