Power　saving　is　an　important　parameter　in　portable　system　design,　which　is　normally　addressed　by　considering　the　energy　consumption　in　each　individual　component　of　system.　But　system　level　approach　is　a　more　promising　way　for　power　saving,　especially　in　embedded　system　design.　A　design　of　portable　radio　frequency　identification　(RFID)　reader,　using　system　level　power　reduction　method　and　working　at　433/868/915　MHz　ISM　frequency,　is　presented　in　this　paper.　The　system　embeds　a　SOC　(System　on　Chip)　peripheral　driving　circuits　to　simplify　the　complex　driving　circuits　of　traditional　LCD　display.　Besides,　a　developed　software　tool　helps　to　improve　the　system　performance,　such　as　the　address　matching,　anti-collision,　checking,　identification,　real　time　calculation　and　data　display.　The　proposed　system　has　advantages　of　simple　structure,　low　cost,　and　low　power　loss.