Various criteria have been developed to describe the aromatic character of cyclic molecules. The electron density of delocalized bonds (EDDB) method was employed in our study because it has been demonstrated excellently to assess aromaticity of different molecular topologies. Especially, EDDB is wellsuited for evaluating global and local electron delocalization through the system of conjugated bonds in non-planar molecules. As depicted in Fig. , the ground state EDDBG plots reveal the effective delocalization of electrons through both large and small rims and the central C-C bonds to form global conjugation systems. Calculations also showed that the local EDDBP(r) index for pyridine moieties (3.928 -3.975) remained nearly the same irrespective of the belt sizes whereas the EDDBP(r) for pyrroles varied from 1.594 to 1.717 depending on the belt size (Table ). The larger the belt, the higher degree (Table ). The computed harmonic oscillator measure of aromaticity (HOMA) (Fig. ) and nucleus-independent chemical shift (NICS) (Table ) were consistent with the results of EDDB method, all supporting aromatic structure of molecules. Noteworthily, the NICS(1)zz values of pyridine and pyrrole on concave surface of belts were around -26 and -17, respectively. More positive NICS(1)zz values were computed on convex surface, being -17--20 for pyridine and -10 --12 for pyrrole (Table ). Different NICS(1)zz values for different side of the aromatic surface of a belt were not unexpected considering the spherical frustum shapes of belts or the distortion of planar structure of each individual heterocyclic moieties to puckered ones.