Abstract: CT has the unique application in reservoir geology field due to its un-destructive, 3 D, combination with computational simulation and so on. Beginning with its character, this paper summarized the development of CT application in reservoir geology and pointed out CT could be used to component and fabric of reservoir rock, characterize reservoir, and monitor fluid transfer processed in pore system online and analysis the distribution of residual oil. With the development of high resolution industrial CT and digital core technology, the combination between 3 D data from CT and digital could not only help to compute petro physical properties, such as porosity-permeability, formation factor, elastic modulus, V_p & V_s, et al., but also quantitative characterize pore-throat structure and simulate percolation based on pore network. Finally, the paper gave a judgment on CT developing, which would be used in more fields, companying the improvement in computer application and exploration of oil and gas.