Ion-exchanged Na (INa) and adsorbed Na (ANa) concentrations have significant impact on the physicochemical properties of coal-derived aerosol, and product yields of soot and tar. INa effectively reduced tar release during primary pyrolysis, thus reducing soot yield. ANa had no clear effect on primary pyrolysis, but was easier to gasify. During the secondary pyrolysis, low-concentrated gasified Na promoted aggregation of aromatics to form soot disordered core and increased soot yield. However, at sufficiently high concentration, Na mainly catalyzed tar cracking. Gasified Na can change size distribution of soot aggregates and promote the conversion of SO2 to SO42-. These two effects of Na were affected by Cl in pyrolysis gas. Na in soot can change the arrangement of graphite-like layers and increase sp(3) hybridized carbon bonding. INa can couple to carboxylate (COO-) and promote formation of ether C-O structures in soot or tar.