Thin films of thulium- and samarium-doped AlN are deposited on silicon (111) substrates at 77 K by RF magnetron sputtering method. 200-400 nm thick films are grown at 100-200 watts RF power and 5-8 mTorr nitrogen, using a metal target of Al with Tm and Sm separately. X-rays diffraction results show that films are amorphous. Cathodoluminescence studies are performed at room temperature and two dominant peaks are observed in Tm at 467 nm from 1D2 →3F4 transition and 480 nm from 1G4 to the ground state 36 transition. Other peaks in the visible region are obtained at 650 nm and 685 nm due to 1G43 G4 → 3F4 and 1D2 →3H 4 transitions. Peaks in the ultraviolet and infrared region are also obtained at 371 nm and 802 nm as a result from 1D2→ 3H6 and 3H4 →3H 6 transition, respectively. Sm gives four peaks at 564 nm, 600 nm, 648 nm and 707 nm as a result of 4G5/2→ 6H5/264G5/2 →6H7/2;6H7/2, 4G5/2→6H9/2 and 4G5/2→6H11/2 transitions. Films are thermally annealed at 1200 K for half an hour in a nitrogen atmosphere. Thermal annealing enhances the intensity of luminescence. ©World Scientific Publishing Company.