Abstract: Porous characters of coal reservoirs in the Ordos Basin tested using the Micrometrics ASAP 2000 automatism isothermal adsorption instrument made in America. Based on analyzing the test data,three variety types of isothermal adsorption and desorption curves are confirmed. The first type is that the hole structure is provided with slit capillary bore; the second is usually the type of upgrowthing one end nipped unparallel crevice; the third belongs to the pores shaped "inkpot". Some kind of usual specific surface distribution curve and accumulative total porous volume distribution curve model of coal reservoirs in the basin are summarized in this paper.