Structural characteristics of 29 Australian coals have been investigated by solid state 13C NMR spectroscopy. A high magnetic field (7.05 T) instrument was used with a spinning sidebands suppression (TOSS) technique to obtain high resolution spectra of coals. Carbon aromaticities of the samples obtained from the experiments are in good agreement with the values derived from normal NMR spectra. They are also compared with aromaticity values derived from FTIR spectra using the Brown-Ladner equation. Good correlations are achieved if the Brown-Ladner equation is corrected for the presence of carbonyl-type carbon species in coals.