The thick-bedded and continuous karst crust only formed in the old stage of geomorphic development. The corresponding landscape is the karst planation surface. The karst planation surface consists of the loose weathering crust and the base weathering front below the crust. Its profile structure is similar to "double surface of leveling" model built by Budel. In the limestone area, the base weathering front is the covered karst. From the Tibet Plateau to Yun-Gui (Yunnan-Guizhou) plateau and Xiang-Gul (Hunan-Guangxi) hills, the covered karst is concomitant with the red weathering crust; all of them are the component of the double-level surfaces of karst planation. But, they belong to the different disintegration stages of planation ...