Metastable　high　entropy　alloys　(HEAs)　and　amorphous　metallic　glasses　(MGs),　with　the　chemical　disordered　character,　are　intensively　studied　due　to　their　excellent　performance.　Here,　we　introduce　Cu　to　separately　constrain　these　two　metastable　materials　and　comparatively　investigate　their　deformation　behaviors　and　mechanical　properties　of　Cu/HEA　FeCoCrNi　and　Cu/MG　CuZr　nanolaminated　micropillars　in　terms　of　intrinsic　layer　thickness　h　and　extrinsic　pillar　diameter　D.　The　metastable　HEA　layers,　as　the　hard　phase　in　Cu/HEA　micropillars,　are　stable　and　dominate　the　deformation,　while　transformation　(crystallization)　occurs　in　MG　which　plays　a　minor　role　in　deformation　of　Cu/MG　micropillars.　The　h-controlled　deformation　mode　transits　from　the　D-independent　homogenous-like　deformation　at　large　h　to　the　D-dependent　shear　banding　at　small　h　in　both　Cu/HEA　and　Cu/MG　micropillars.　Although　both　Cu/HEA　and　Cu/MG　micropillars　exhibit　a　maximum　strain　hardening　capability　controlled　by　h,　the　former　manifests　much　lower　hardening　capability　compared　with　the　latter.　The　intrinsic　size　h　and　extrinsic　size　D　have　a　strong　coupling　effect　on　the　strength　of　Cu/HEA　and　Cu/MG　micropillars.　The　strength　of　strength　of　Cu/HEA　micropillars　exhibits　the　D-dependent　transition　from　＇smaller　is　stronger＇　to　＇smaller　is　weaker＇　with　increasing　h.　By　contrast,　the　strength　of　Cu/MG　micropillars　exhibits　the　transition　from　bulk-like　D-independent　behavior　at　large　h　to　small　volume　D-dependent　behavior　(smaller　is　stronger)　at　small　h.　©　2020