Twelve isomers of B₂₄N₂₄ fullerene-like cage clusters were studied with density functional theory (DFT) B3LYP/6-31G^* method. The geometries, harmonic frequencies, character of chemical bond and relative energies were discussed. The result indicates that the S₈ symmetry isomer of B₂₄N₂₄ cluster h, which contains 8 four-, 16 six- and 2 eight-membered rings, without direct B-B and N-N bondings, turned out to be the ground state. It is noted that by increasing the B-B and N-N bond pairs and the number of five-membered ring content, the stability of the B₂₄N₂₄ cage is decreased. The order of stabilities for the twelve isomers is h>a>b>i>g>l>c>k>j>d>e>f.

Key words: B₂₄N₂₄ cluster, DFT, structure and stability, boron nitride