Hexagonal　NaY0.95Yb0.03Er0.02F4　microcrystals　with　different　morphologies　were　prepared　by　hydro-thermal　synthesis　with　three　controlling　methods,　including　addition　of　different　amount　of　EDTA,　addition　of　different　surfactant　including　CTAB,　P123　and　SDBS　and　using　different　thermal　solvents　including　water,　ethanediol　and　polyethyleneglycol.　The　synthesis　method　can　be　described　as　following:　trivalent　nitrate　stock　solutions　of　1　mol/L　with　ratio　0.95/0.03/0.02　of　Y3+/Yb3+/Er3+　were　prepared　by　dissolving　the　corresponding　metal　oxide　in　concentrated　nitric　acid　at　elevated　temperatures　and　label　as　A.　Certain　concentration　solution　of　EDTA,　P123,　CTAB,　SDBS,　NaF,　and　NH4HF2　were　prepared　as　candidate.　In　a　typical　procedure,　a　certain　amount　of　EDTA,　CTAB,　P123,　and　SDBS　were　added　into　20　mL　A　sulution.　After　vigorous　stirring　for　30　min,　certain　mol　NaF　was　added　drop　by　drop,　the　pH　value　of　solution　was　adjusted　to　3.0　by　the　addition　of　1　mol/L　HF　or　NaOH,　and　then　stirring　continued　for　30　min.　Then　the　emulsion　mixture　was　moved　to　Teflon-lined　autoclave　and　incubated　in　oven　at　195°C　for　4　h.　The　products　were　washed　by　deionized　water　and　ethanol　three　times　respectively,　and　then　dried　in　oven　at　60°C.　Phase　structure　and　crystal　morphologies　were　characterized　by　XRD　(X-ray　powder　diffraction),　SEM　(scanning　electron　microscope)　and　TEM　(transmission　electron　microscope)　methods.　Analysis　results　indicate　that　the　crystal　growing　direction　changed　from　[001]　to　[100]　and　bond　distances　between　F-　and　Y3+/Yb3+/Er3+　were　enlarged　while　bond　distance　between　F-　and　Na+　was　reduced　with　the　increasing　EDTA　amount.　The　crystal　morphology　was　not　changed　by　adding　CTAB　surfactant　compared　with　no　surfactant　adding　sample,　while　microtubes　were　obtained　when　P123　was　added　as　surfactant,　and　micrograins　morphology　mixed　with　some　smaller　hexagonal　NaYF4　when　SDBS　was　added　as　surfactant;　crystal　sizes　and　exposure　lattice　plane　were　also　tuned　with　different　thermal　solvents.　Crystal　growing　mechanism　of　different　morphologies　was　discussed　in　the　manuscripture.　Upconversion　(UC)　luminescence　emission　spectra　and　decay　time　curves　of　different-morphological　samples　were　obtained　using　Edinburgh　instruments　FSLP920　fluorescence　spectrophotometer　with　980　nm　OPTEK　OPO　LASER　excitation.　The　lifetimes　of　521　and　541　nm　emission　were　fitted　by　single　exponential　decay　function.　Luminescence　property　analysis　results　show　the　intensity　and　lifetime　of　spectra　emission　is　interrelated　with　crystal　morphology,　the　emission　intensity　is　enhanced　with　reducing　of　the　thickness　of　micrograins,　and　the　intensity　of　the　smallest　microstick　is　the　strongest　among　all　the　samples.　The　lifetime　fitted　results　show　the　decay　time　constants　and　rising　time　constants　are　different　of　different-morphological　NaY0.95Yb0.03Er0.02F4,　indicating　that　their　energy　transfer　models　are　different　during　UC　emission.　This　manuscripture　may　be　helpful　for　morphology-controllable　synthesis　of　UC　materials　with　super　luminescence　performance.　©　2013　Shanghai　Institute　of　Organic　Chemistry,　Chinese　Academy　of　Sciences.