AbstractNatural abundance13C chemical shift anisotropy (CSA) spectra of the aromatic CH carbons of bisphenol‐A (BPA) residues were measured for BPA polycarbonate (BPAPC) and polyarylate (PAr) films at different temperatures by selective excitation switching angle sample spinning (SESASS) NMR spectroscopy. The CSA spectra thus obtained were analysed in terms of the two‐site exchange model for the flip motion of the phenylene group. In BPAPC, wide distributions in flip angle around 0° and 180° are well revealed under the situation of the first exchange limit for the flip motion and the widths become significantly broader with increasing temperature. These results are in good agreement with those of the previous2H NMR analyses. Similar wide distributions in flip angle are also recognized even at lower temperatures for PAr, which is a non‐crystalline polymer composed of BPA and phthalic acid residues, suggesting more enhanced phenylene motion in this polymer. Moreover, the CSA spectra obtained for PAr above 60°C are found not to be reproduced by using the simple two‐site exchange model primarily based on the flip motions around 0° and 180°, probably owing to the onset of larger scale random motion of t