Abstract: The image resolution of industrial X-ray computed microtomography (CMT)with focal spot of X-ray source less than 5 micrometer is quite better than that of conventional focal spot CT.In petroleum exploration and development research computed microtomgraphy was used to many technological areas with revolutionary achievements: (1) determination of the basic petrophysical properties of cores - calculating and illustrating distribution of buck density, porosity and fluid saturation; (2) imaging of micro- scopic porous ofrock- intuitive describing micro-structure of porous and oil-water distribution in porous; (3) evaluatian of special lithological reservoir cores- investigating characteristics of cabonatite mogatic rock etc., that can not be done by conventional methods, (4) analysis of core flooding and enhanced oil recov- reconstructing macroscopical distribution of oil and water in cores, (5) application of other aspects: screening core, evaluation offormation damage, evaluating rock mechanical properties of cores, and so on.