Abstract: In order to improve gas recovery of low rank coal reservoir, several researches, like the pressure and flow velocity sensitivity analysis and its corresponding influence on coalbed methane drainage have been conducted in Dafosi No.4 coal seam. Research results show that when flow rate is greater than the critical rate, reservoir permeability will decrease slightly. The low rank coal reservoir has strong pressure sensitivity and irreversibility. Test shows that huge pressure increase could cause 90% loss of permeability, and even after pressure release, permeability can never recover to the original degree and could cause 60% permanent loss. As a result, in order to decrease the influence of reservoir sensitivity on coalbed methane well, a slow, continuous and gradual pressure decreasing protocol should be applied.