Sensitive　materials　are　widely　used　in　the　field　of　optical　fiber　sensing　because　of　their　unique　advantages　such　as　rich　types,　controllable　composition　ratio　and　diverse　structure　distribution.　In　this　paper,　the　surface　of　long-period　fiber　gratings　with　InGaZnO　[(In2O3):(Ga2O3):(ZnO)]　nano　films　with　different　compositions　were　coated　by　pulse　laser　deposition　(PLD)　technology.　The　best　sensing　ratio　and　the　high　sensitivity　sensing　of　the　refractive　index　of　long-period　fiber　grating　(LPFG)　were　achieved　through　the　analysis　of　the　influence　of　different　ratios　of　InGaZnO　nano　films　on　the　refractive　index　sensing　characteristics　of　grating.　High　sensitivities　of　337　nm/RIU　(refractive　index　unit)　and　145　dB/RIU　of　the　LPFG　are　achieved　when　the　best　doping　ratio　of　InGaZnO　is　7:1:2.