Regenerated silk fibroin/nano-TiO2 composite films in different ratios were prepared by sol-gel method.UV-Vis spectroscopy and SEM observations revealed that the nano-TiO2 particles are well dispersed in the regenerated silk fibroin.Diameter of the nano-TiO2 particles was determined as about 80 nm.FTIR and two dimensional FTIR correlation spectroscopic studies indicated that the formation of nano-TiO2 particles leads to the aggregation structural changes of silk fibroin，in which strong hydrogen bonding was reconstructed from the rupture and rearrangement of the weak and free hydrogen bonding of the N—H groups.At the same time，the alignment of the silk fibroin molecules tends to be in an ordered form，and the crystal structure of fibroin in the composite films were transformed from Silk Ⅰ to a typical Silk Ⅱ form.