Atomic arrangements, substitution patterns, and properties of BN-doped C-60 fullerene have been investigated using semiempirical MNDO and density functional theory (B3LYP/3-21G). The BN units prefer to stay together following "hexagon-hexagon junction", "N-site attachment", "hexagon filling" and "continuity" rules; this characteristic of atomic arrangement is independent of the compositions of BCN fullerenes. Charge redistributions after each BN substitution seem to play a guiding role for selecting the next carbon pair to be replaced by BN. The incoming BN group seeks the most highly charged carbon pairs. Up to twenty carbon pairs Of C-60 may be replaced by heteroatoms. The band gap (HOMO-LUMO gap) strongly depends on the number of BN units and their filling patterns. BN-substitution increases the electron donation capacity of fullerene.