FT-IR spectroscopy was used to study the specific interactions in polyacrylonitrile-silk. fibroin (PAN-SF) and poly(acrylonitrile-co-methyl acrylate)-silk fibroin (PANMA-SF) blends. No specific interaction was found in PAN-SF blends. in PANMA-SF blends, however, a new 1703 cm(-1) band, assigned to be hydrogen-bonded carbonyl groups of PANMA, appears, and its intensity depends on the compositions of the blends and the MA contents in PANMA. Furthermore, when the sample was heated, considerable changes in position and intensities of the hydrogen-bonded bands, in both stretching regions of the carbonyl group of PANMA and the hydroxl group of SF, were found, and these changes were irreversible on cooling. Finally, we suggested that the bands of hydrogen bonds in PANMA-SF blends may be the average result of several kinds of possible hydrogen bondings.