Abstract: Based on the adsorbing-swelling experiments of coal samples，the self-adjusting effects of lean coal to antracite were revealed．Then，the influence of the effects on coal reservoir permeability was analysed and the coupling mathematical model between the effective-stress effect，coal matrix shrinkage effect an dpermeability was established ．The degressive rule of high-rank coal reservoir permeability during the coalbed methane recovery and the geological significance of the discovery were discussed．