The　high-crystallinity　and　low-defect-density　microcrystalline　silicon　films　(mu　c-Si:H)　was　prepared　by　using　a　new　hot-wire-assisted　microwave　electron　cyclotron　resonance-chemical　vapor　deposition　(HWAMWECR-CVD)　system.　In　this　system　the　hot　wire　plays　an　important　role　in　suppressing　the　growth　of　a-Si:H　in　favor　of　mu　c-Si:H,　thus　improving　the　physical　properties.　The　experimental　results　show　that　the　mu　c-Si:H　film　prepared　by　using　this　new　system,　the　crystalline　volume　fraction　is　increased　from　16.4%　to　63.2%,　the　photoconductivity　is　increased　by　two　orders　of　magnitude,　the　optical　band　gap　is　decreased　to　1.59eV,　and　the　light-induced　degradation　keeps　almost　constant　compared　to　that　prepared　by　conventional　system.　(c)　2005　Elsevier　Ltd.　All　rights　reserved.