Karst landform is widely distributed and diverse in China, rarely seen in the world. Carbonate rocks (such as limestone, dolomite, gypsum, rock salt, etc.), as material basis for the development of karst landform, are widely distributed in China. According to incomplete statistics, the total area is 2 million square kilometers, including 1.3 million square kilometers of the exposed carbonate rock area that accounts for about 1/7 of the total national area; and the buried carbonate rock area is about 700,000 square kilometers. Carbonate rocks are distributed in all provinces and regions of the nation, most widely distributed in Guangxi, Guizhou and eastern Yunnan, and widely distributed in  western Hunan, western Hubei, eastern Sichuan, Shandong, and Shanxi, etc.