Two new polychalcogenide complexes of thulium are obtained by the interaction of (Cp′′′ = 1,3,4-tris(tert-butyl)cyclopentadienide) (1) with elemental sulfur under different conditions: (2) and (18-cr-6 – 1,4,7,10,13,16-hexaoxa cyclooctadecane) (3). A reaction of complex 2 with CS2 in toluene is studied. It results in compound (4) that is the first example of Tm(III) perthiocarbonate complex. Structures of 2-4 are determined by single crystal X-ray diffraction.