Abstract: The effects of gelatin α subunits and maillard reaction on the properties of gelatin-sodium alginate ( SA) blend films were investigated by measuring the mechanical properties, color, fluorescence intensity and fourier transform infrared spectroscopy ( FTIR) .The mechanical properties of gelatin α subunits-SA blend films were decreased after storage at 0 ℃, 75% relative humidity ( RH) for 72 h, while the fluorescence intensity was increased.When α1-SA blend films were stored for72 h, the increasing extent of b*value was 64.0%, which was higher than that of G-SA blend films and α2-SA blend films.It was revealed that the maillard reaction could occur between α subunits and sodium alginate, and α1-subunit was easier to be reacted than others through FTIR analysis.It was concluded from the results of this study that the color of gelatin α subunits-SA blend films became yellow during the storage at 0 ℃ and 75% RH.