Abstract: This paper is concerned with the reservoir characteristics and genesis of secondary pores of the Shan-2 Member of Shanxi Formation (Lower Permian) in the eastern of Ordos basin. The main types of pores are the primary intergranular pores and the dissolution pores. The scanning electron eastern analysis of thin sections shows that the secondary pores were mainly formed by dissolution of matrix. Besides the sedimentation processes, the intensity of dissolution was affected by the rock types and matrix content. Dissolution was strong in the deltaic sandbodies where the coal-seams are found and the hydrocarbon generating center is located nearby, and therefore the pores are well developed.