Fe(NO3))-SiO2glasses were prepared by hydrorlyzing silicon alkoxides with various amount of ferric nitrate hydrate following the sol-gel process. The gel glasses were allowed to dry completely at room temperature then several thermally treatments were done. The thermal transition was studied with differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). The structural features of the glassy materials were analyzed by means of infrared (IR) spectroscopy and X-ray diffraction (XRD). The samples with a higher concentration of 30 % mole of iron existed in the crystalline structure; the thermal transitions did not affect the crystalline structure of these mixed samples as indicated by the X-ray diffraction. The IR spectra indicated the existence of Si-O-Fe bond. The thermal analysis indicated similar heat transitions for the glass as the pure iron nitrate with some modification due to the interactions with the silica network.