In　this　paper,　two　kinds　of　methods　of　calculating　the　hydrogen　content　of　a-Si:H　thin　film　by　means　of　the　wagging　mode　and　the　stretching　modes　of　infrared-transmission　spectra,　are　investigated.　The　reason　for　the　difference　in　these　two　calculation　results　is　analyzed.　If　the　contents　of　SiH(2)　and　(SiH(2)),　are　indicated　in　terms　of　a　structure　factor　F=(I(840)+I(880))/I(2000),　it　is　shown　that　the　calculation　results　obtained　from　the　two　different　methods　are　almost　equal　when　the　refractive　index　n　is　approximately　3.4　or　the　fitting　thickness　is　between　0.71　and　0.89　mum　in　the　case　of　a　small　F　It　is　shown　that　the　ways　of　fabrication　of　thin　film　can　influence　silicon-hydrogen　bonding　configuration　of　a-Si:H　film,　and　different　ways　of　fabrication　can　lead　to　different　contents　of　SiH(2)　and　(SiH(2))(n).　The　uniformity　of　the　thin　film　with　a　big　F　is　bad.　In　this　case,　there　is　great　difference　between　the　thickness　measured　by　the　SurfCom408A　surface　profile　apparatus　and　the　thickness　obtained　by　fitting　the　fringes;　and　the　hydrogen　contents　of　a-Si:H　films　obtained　by　means　of　the　wagging　mode　and　the　stretching　modes　are　different,　too.　But　the　fabrication　of　the　MWECR　CVD　assisted　by　CAT　CVD　can　effectively　restrain　the　formation　of　SiH(2)　and　(SiH(2))(n).