Shale　gas　is　becoming　an　increasingly　promising　alternative　energy　resource　because　of　its　high　efficiency　and　environment-friendly　characteristic.　The　amount　of　adsorbed　gas　on　the　shale　matrix　surfaces　and　dissolved　gas　in　the　shale　matrix　bulk　is　the　dominant　factor　in　the　long-term　productivity　of　shale　reservoir.　Although　experimental　measurements　have　been　extensively　carried　out　to　investigate　the　gas　adsorption　and　diffusion　properties　in　the　shale　matrix,　they　cannot　provide　the　detailed　information　on　the　microscopic　transport　mechanism　of　shale　gas　during　the　gas　production　process.　Molecular　simulation　can　accurately　visualize　the　gas　adsorption/desorption　and　diffusion　processes　in　the　shale　matrix.　In　the　present　study,　the　recent　research　advances　of　molecular　simulation　on　gas　adsorption/desorption　and　diffusion　in　the　shale　matrix　are　reviewed.　Firstly,　the　density　functional　theory　(DFT)　for　shale　gas　molecule　desorption/adsorption　on　the　surface　of　the　matrix　crystal　is　illustrated.　Then,　the　grand　canonical　Monte　Carlo　(GCMC)　method　predicting　the　amount　of　shale　gas　desorption/adsorption　in　the　shale　matrix　crystal　is　introduced.　Finally,　molecular　dynamics　simulation　(MD)　for　gas　diffusion　in　the　shale　matrix　is　elucidated.　Further　developments　of　the　molecular　simulation　method　in　shale　gas　production　are　also　discussed.　©　2018,　Science　Press,　Institute　of　Engineering　Thermophysics,　CAS　and　Springer-Verlag　GmbH　Germany,　part　of　Springer　Nature.