In karst area, formed jointly under actions like new tectonic raising upwards, intense erosion and corrosion by water flow as well as collapse, the valley with steep brae and larger depth than its width is generally called karst gorge. It is a karst regional synthesis including karst gorge landform and coexisted peaks, body of water, rocks and organisms. In carbonatite distribution area, because the fault, fissure and joint are positions where water flow are concentrated, erosion and corrosion occur, therefore, karst gorge is easy to be formed.

The types and shapes of karst gorge are various. According to the morphology,karst gorges can be divided into V-shape gorge, narrow gorge (steep valley slope, depth much larger than width), box shape gorge, earth fissure shape (thin strip type) gorge, etc..

According to the causes of the formation,it can be classified into surface river gorge (gorge formed during the development process of surface river to the underground, developing both in karst area and non-karst area) and underground river gorge (gorge formed during development process of underground river to surface, exclusive in karst area).