This paper develops an MILP model for designing multi-period natural gas transmission network to determine the connections of pipeline and the sites of compressor stations with consideration of terrains and obstacles. Equations of mass balance of network nodes, pressure drop of pipelines and pressure increase of compressors are all taken into account. A piece-wise linearization method is applied to the model. Four cases of natural gas transmission networks in Shanxi province (China) are studied. The result illustrates that the model can tackle complicated natural gas transmission network optimization problems. The developed model is of practical value for natural gas sales enterprises to minimize the construction cost and is a good designing reference for construction contractors. (C) 2017 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.