Silk fibroin (SF)/gelatin (G) blend films were prepared and used as subject for observation of the effect of cross-linked agent; poly(ethylene glycol) diglycidyl ether (PEGDE). The Thai silk called Nang-Lai cocoons were used for preparation of SF solution. They firstly degummed with 0.5% Na2CO3 solution to exclude sericin before dissolving with CaCl2: Ethanol: H2O (1:2:8 by mole) solution with stirring at 90 °C for about 1h. In this work, the ratio between SF and G solution was fixed at 2/1 (v/v) and then prepared the blend films by evaporation method. Some properties including morphology, secondary structure, thermal properties of the blend films were analyzed. FTIR results indicated that the SF/G blend films composed of α-helix mixed β-sheet forms than that of native SF or G films. In addition, cross-linked agent helped to enhance the β-sheet formation and increased the strength of the blend films. Moreover, morphology of blend films was gradually smooth on their texture when added the cross-linked agent compared to both native films. Thermal properties showed that increase of the PEGDE content results to the higher of decomposition temperature. The results strongly provided that PEGDE could be used for enhancing the strength properties of SF/G blend films by changing the structure from α-helix to β- sheet form. © Research India Publications.