This paper, taking lacustrine carbonate rocks of Guanzhuang Group of Pingyi Basin for example, aims at studying the paleogeographic significance of lacustrine carbonate rocks. Taking the sedimentary theory as guiding theory and based on the outcrop section,we analyze the formation and sedi- mentary features of Guangzhuang Group. Combined with the formation and evolution of the basin, we also analyze the conditions of sedimentary environ- ment, such as the paleontology, ancient climate, content sources, physical and chemical conditions of water medium, and so on, and clarify the paleogeo- graphic patterns and characteristics when Gaanzhuang Group was deposited. The study suggests that the basin was a warm inland environment when lacus- trine carbonate rocks were deposited. And the tectonic movement was relatively static, paleotopography was relatively flat, which was favorable to the deposi- tion of the lacustrine carbonate rocks, and carbonate concentration in the environment of shallow water, low and middle energy,little terrigenous fragmental materials. Thus it is demonstrated that the favorable paleogeographic setting for lacustrine carbonate strata was the sedimentary environment with relatively static tectonic movement, flat terrain, shallow water and low energy.