Abstract: According to the theory of crystallization chemistry, thermodynamics and kinetics, the process of droplet-like phase-separation of CaO-Al₂O₃-SiO₂ glass
was simulated by using TEM, image analyzer and computer. The mathematics and logical model of phase-separation was developed on the basis of phase transition theory and
experiments. The key factors of following logarithmic normal distribution are that critical sizes of droplet phase nuclei must change in a certain range for the droplet-like phase-separation
controlled by the mechanism of nucleation-growth; relative growth rate of droplet phase locates at 5%--10%. The distribution type has no relationship to the absolute values of critical sizes
when phase-separation takes place, and to the droplet phase diameter when the droplet phase stops growing. This simulation method leads to a new way to control nanometre structure of glass and make a noval glass
materials with some special properties.

Key words: computer simulation, glass, phase-seperation