Economic transformations in Poland to market conditions caused changes in mining activity and mode of evaluation of accessible resources. It resulted in changes of the amount of resources presented in the inventory, especially drastic in the case of black (bituminous) coal resources and reserves, not related to the exploitation. The main reasons for the changes are: limitation of black coal resources evaluation to a depth of 1000 m, changes of resources categorization due to mine closure, and reevaluation of part of resources as prospective resources. The main factors that restrain mining and force to leave some part of resources as not mineable are: a) land utilization (residential and industrial building) that preclude mining activity, b) economic conditions of mining and financial policy of mines, c) in the case of black coal long-wall mining which is aerially limited by tectonic features of coal-bearing series. There is lack of sufficient legal regulations for the protection of mineral deposits, implemented through the protection of the area of deposit occurrence against such land utilization, which may preclude future mining.