Abstract The 13 C nmr spectra of 2-or 3-monosubstituted furo [2, 3-b]-1a-1j, furo [3, 2-b]-2a- 2j, furo [2, 3-c]-3a-3j and furo [3, 2-c] pyridine derivatives 4a-4j are reported. Effects by change in annelation and substituent effects on 13 C chemical shifts and carbon-proton coupling constants are discussed. The spectra of benzo [b] furan derivatives 5a-5j having the corresponding substituent are also reported for comparison.