Pores　of　shale　exhibit　multiscale　characteristics,　and　pore　characterization　is　challenging　due　to　the　complexity　of　pore　systems.　Currently,　research　is　focused　on　nano-submicron　pores,　but　the　structure　of　micrometer-scaled　pores　is　not　well　understood.　In　this　research,　an　investigation　of　the　three-dimensional　pore　network　of　the　Chang　7　shale　in　the　Ordos　Basin　of　China　was　conducted,　in　order　to　provide　an　insight　into　the　full　characteristics　of　pore　systems.　Nano-CT　and　micro-CT　scanning　technology　was　used　to　comprehensively　delineate　the　pore　structure　at　different　scales,　for　further　understanding　the　gas　storage　mechanism　in　shale　rocks.　Results　show　that　the　radius　of　micro-scale　pores　ranges　from　1　to　15　mu　m,　with　an　average　of　2.8　mu　m,　and　pores　with　radii　of　1-5　mu　m　occupy　approximately　90%　of　all　the　pores.　For　the　nano-scale　pores,　the　size　ranges　from　86　to　2679　nm,　with　an　average　of　152　nm,　yet　it　has　a　rather　concentrated　distribution　within　300　nm.　The　nano-scale　pores　constitute　most　of　the　pore　amount　in　the　shale,　whereas　the　micro-scale　pores　constitute　most　of　the　pore　volumes.　Moreover,　the　results　show　that　more　than　70%　of　nano-scale　pores　in　the　Chang　7　shale　are　isolated　pores,　indicating　that　pore　bodies　formed　in　the　shale　reservoir　have　poor　connectivity.　Positive　linear　relationships　between　pore　sizes　and　the　number　of　pore　throats　at　the　micro-scale　and　nano-scale　were　both　obtained,　suggesting　that　larger　pores　tend　to　have　better　connectivity　than　smaller　pores.