To discover the water structure in glass, two silicate glasses were synthesized under different melting atmospheric conditions. Fourier transform infrared spectrometric analyzer was used to study the OH contents and the infrared spectra bands in 1300-4000cm-1 of the glasses. The research shows that water contents of glass samples melted under air atmosphere and oxyfuel firing atmosphere are 0.0323wt% and 0.0512wt% respectively. The infrared absorptions in 1300-4000cm-1 band are dominantly related with water dissolved in glass melt. Water existing in glass is mainly in the form of Si-OH, in addition with some free OH connected with metal cations. The IR absorption of ferrous ion in glass is near 3430cm-1, while the IR absorption near 2500 cm-1 does not belong to the vibration of KOH.