Abstract: The acidolysis simulations of sandstone are made to study the evolution and recognition of the secondary porosity of sandstone. The paper mainly discussed about various changes of mineral composition, porosity, permeability and pore texture during acidolysis of sandstone, as well as various dissolutions observed on the thin sections of acidolysis casts. Based on what mentioned above, the evolutional process and the conditions of secondary porosity in sandstone are described in this paper.