This　paper　presents　a　low-power　and　low-noise　front-end　amplifier　(FEA)　dedicated　to　recording　and　preprocessing　biomedical　signals　for　brain-machine　interface.　The　FEA　employs　a　current-reused　architecture　which　adopts　an　inverter-based　differential　input　stage　to　achieve　considerable　g(m)/I　efficiency　and　low　noise.　With　a　carefully　designed　common-mode　feedback　circuit,　the　output　common-mode　voltage　of　the　fully-differential　FEA　is　stabilized　within　an　acceptable　margin　of　error　about　1　mV.　All　transistors　in　FEA　operate　in　the　sub-threshold　region,　realizing　low　power　consumption.　This　current-reused　FEA　implemented　in　a　CMOS　0.18-mu　m　technology　provides　a　noise　efficiency　factor　(NEF)　and　power　efficiency　factor　(PEF)　of　1.6　and　2.56,　respectively,　corresponding　to　an　input-referred　noise　of　2.37　mu　V-rms.　This　FEA　consumes　only　2　mu　A　current　from　1　V　supply　and　the　active　area　is　0.2　mm　x0.2　mm.