In this paper, the authors investigated petrological characteristics and reservoir properties of dolomite reserviors in the Cambrian of the eastern Tarim Basin. The dolomites in eastern Tarim Basin can be subdivided into two categories, replacement dolomite and crack-cavity-filled dolomite. The reservoir space in dolomites is predominated by inter-crystal pore, dissolved pore, stylolite pore and cracks and fractures. The most common reservoir space is mainly the overlapped complex of cracks and cavities. The distribution of the dolomite reservoirs were controlled by the sedimentary facies, diagenesis (dolomitization, cementation, disolution), and fractures.