The investigation results of the bonding structure of CaO-SiOslag by means of molecular dynamics simulation are presented. The characteristics of partial radial distribution function g(r) are in good agreement with the measurement of X-ray diffraction, and the variation of Qwith different SiOtefrahedra following the change of Xis consistent with the results of Raman spectroscopy. The partial vibrational density of states F(ω) shows that two bands appear in the range of 636-737 cmand 800-1200 cmrespectively which are also consistent with Raman spectroscopy.