Abstract: A new technique for measuring simultaneously adsorption rate and temperature variation in zeolite hasbeen developed.The transient temperature process during adsorption of gas on zeolite was analyzed by meansof a simple model.It was found that the diffusion of gas in zeolite crystallines could be made almost iso-thermal if the experimental conditions were appropriately designed.Thus the thermal effect on determinationof diffusion coefficient of gas in zeolite could be neglected.