An evaluation method of Tm 3+ doped glasses for upconversion laser was given.In this paper.the upconversion luminescence of Tm 3+ in geminate and telluride glasses was studied.Optical gains of the upconversion luminescence were measured.The gain coefficient G GD of 1 D 2 equaled 0.36 mm -1 in geminate, G TD equaled 1.79 mm -1 of 1 D 2 and G TD equaled 1.65 mm -1 of 1 G 4 in telluride.With the results the possibility of upconversion lasing under 650 nm excitation was discussed.Telluride glass has an advantage for laser operation compared with geminate glass.