The C-13 NMR spectra were measured for three isomers of Tm@C-82, which is one of the divalent metallofullerenes. The molecular symmetries were determined for each isomer: isomer I has Q symmetry, isomer II has C-2 symmetry, and isomer III has C-2v symmetry. Moreover the cage structure of Tm@C-82(III) was found to be C-82(9). As a result, it was revealed that Tm@C-82(III) has a cage identical to that of La@C-82, which is one of the trivalent metallofullerenes.