The sorption kinetics and equilibria of N₂ in pelletized zeolite 4A and 5A by the gravimetric method were studied theoretically and experimentally at the range of 273-303 K and 0-0.8 atm. The diffusion rate of N₂/4A system was determined by micropore diffusion. The micropore diffusion time constants of N₂/4A system showed no significant concentration dependence. The micropore diffusion rate and diffusional activation energy in N₂/4A system could be explained by the ratio of adsorbate kinetic diameter to micropore diameter. On the other hand, the diffusion rate of N₂/5A system was significantly affected by macropore diffusion. The effective macrpore diffusivity of N₂/5A system was increased moderately with sorbate pressure and was well predicted by using average macropore diffusivities, porosities, and slopes of isotherm. The effects of external film heat transfer by heat of adsorption were significant for N₂/4A and N₂/5A systems. The rates of external film heat transfer depended not on the adsorbent, but on the thermal properties of the adsorbate.