Abstract: A fading kinetics model，T=1-B-kC₀exp(-bt), was deduced on the basis of transition probability, b, of silver colloid forming silver ion, the
solutions of the model were given by applying the measured fading kinetics parameters with a computer, and the measured fading kinetics curves and the
calculated fading kinetics curves of F-series photochromic glass containing AgX were compared. The results indicate that the fading kinetics model
preferably explains the fading process of the photochromic glass, and the transition probability, b, accurately expresses fading rate of fading kinetics. The calculated curves and measured curves of fading kinetics of F-series
photochromic glasses containing AgX are almost similar. So these results further prove that the fading kinetics model is effective to explain the
fading process, and the theory as the basis of the fading model is correct.

Key words: photochromic glass, AgX, kinetics model, fading