A　series　of　high　quality　ZnWO4:Tm3+　single　crystals　were　grown　with　Czochralski　method.　The　concentrations　of　thulium　ions　were　0.1,　0.3,　0.5,　0.7　and　1.0　mol%,　respectively.　When　ZnWO4:Tm3+　single　crystals　were　excited　by　807　nm　laser,　the　up-conversion　luminescence　peaks　at　486　and　695　nm　which　corresponded　to　transitions　1G4--＞3H6　and　3F3--＞3　H6,　respectively,　were　detected.　The　intensity　of　695　nm　luminescence　varied　with　the　pump　power　in　a　double　logarithmic　relation　whose　indexes　were　0.8　and　1.1　orders,　respectively.