At　present,　though　Tm3+　up-conversion　(UC)　luminescence　of　NaYF4co-doped　with　Tm3+　and　Yb3+　as　sensitizer　has　the　highest　efficiency,　it　is　not　efficient　enough　for　application.　In　experiment,　Sc3+　was　used　to　dope　Na　(Y1-x-y,　Tmx,　Yby)F4,　and　effects　of　different　concentrations　of　Sc3+　co-doping　on　the　UC　luminescence　of　Na　(Y1-x-y,　Tmx,　Yby)F4　was　investigated.　Phase　component　and　crystallite　size　of　hydro-thermal　synthesis　samples　were　characterized　by　the　X-ray　diffractometry　and　transmission　electron　microscopy.　The　UC　luminescence　and　fluorescence　lifetime　were　analyzed　by　the　fluorescence　spectrophotometry.　Analysis　results　indicated　the　UC　efficiency　can　be　further　enhanced　by　co-doping　with　mole　fraction　of　5%　Sc3+,　and　the　UC　intensity　is　twice　that　without　Sc3+　co-doping.　Furthermore,　lifetime　of　the　fluorescence　does　not　change　obviously.