The effects of different calcination temperatures, load capacities and load methods on the monolayer dispersion of CaCl2 onto silica gel were studied by XRD. It was indicated that calcination temperature of 500℃ is enough for the monolayer dispersion of CaCl2 onto silica gel and the monolayer dispersion threshold is the lower than 0.4g/g. The method of impregnation in aqueous solution is the more suitable than the method of dry mixture for thermal dispersion of CaCl2 onto silica gel. At the same time , it is proved by XRD and FT-IR that the skeleton structure of silica gel will be kept at the lower calcination temperature such as 500℃ but changed obviously when the sample is calcined at 600℃.
