A　novel　compact　two-side　anti-metal　tag　antenna　for　radio　frequency　identification　(RFID)　applications　is　proposed　in　this　paper.　The　proposed　tag　antenna　is　composed　by　three　aluminum　patches　separated　by　two　layers　of　foam　substrates.　Particularly,　the　middle　patch　of　the　antenna　is　designed　as　three　nested　deformable　rings　for　the　miniaturization　of　antenna　and　realizes　better　power　transmission　coefficient　(PTC)　between　the　antenna　and　tag　microchip.　The　antenna　operates　at　the　center　frequency　of　915　MHz　and　maintains　a　compact　size　of　35　mm×22　mm×2.15　mm　(0.1068λ0　×0.0671λ0　×0.0066λ0).　When　the　front　or　back　side　of　the　tag　antenna　is　mounted　on　a　large　background　metallic　plate　and　tested　with　an　effective-isotropic-radiated-power　(EIRP)　of　4　W,　the　antenna　can　achieve　the　maximum　read　distances　of　6.23　m　or　6.08　m.　The　tag　antenna　shows　various　advantages,　including　small　size,　low　profile,　and　good　antenna　performance.　Most　importantly,　the　proposed　tag　antenna　has　two-side　anti-metal　property　compared　to　a　traditional　single-side　anti-metal　antenna,　which　fulfills　the　emerging　demands　in　the　industrial　internet　of　things　field.　©　2022,　Electromagnetics　Academy.　All　rights　reserved.