Dolostones with natron are widely deposited from member Eh2 to the upper sub-member Eh3 in the Anpeng area of the Biyang sag in the Nanxiang basin. Dissolved porous and caved reservoirs mainly occur in dolostones with natron. Caves were formed from lumpy natron dissolution and dissolved pores from the scattered natron dissolution. Part of the dissolution pores were from clay-scale albitite dissolution. Vertically, dissolved porous and caved dolostone reservoirs are distributed in natronic dolostone, evolving from sandstone , mudstone to natron, and the relevant geological unit is member Eh23. Horizontally, these reservoirs are adjacent to the natron beds, and the relevant area is around wells Yun 2,Yun 3 and Bi 100 etc.