Abstract: Laboratory investigation was conducted to determine the influence of discontinuity length and density on permeability of Nigeria coal seams to serve the advantage of water infusion in coal seam mining. This study presents the measured equivalent permeability results and its relevance to water infusion in coal seams. The laboratory results indicated that the coals have equivalent permeabilities of 10 4 to 10 3 m s 1 and the permeability coefficient is mainly dominated by the percentage of porosity and the crack number. The laboratory data provide a base for assessment and prediction of water inflow into the seams during coal seams mining.