Weathering crust palaeokarst develops in Middle Ordovician Majiagou carbonate rock and some evaporates in central Ordos Basin. On the basis of understanding the palaeo-geologic maps, and choosing the tuff from the first bottom bed of the Sub-member 4 in Majiagou Member 5 as the guide bed, mapping of the Pre-carboniferous palaeokarst landform in central Ordos Basin is finished. The research area can be divided into 4 palaeokarst landform units from west to east: a) karst highland; b) karst platform (level platform); c) karst basin; and d) karst platform and karst grooves. Strata of the karst highland tilt westwards and the eroded karst face shows well-ordered distribution from old to young in geological age from west to east. The karst platform, in which formational rock of karst caves commonly develop within many thin beds, relieves gently and is relatively low and flat in topography and it is now the major production area of gas from Majiagou Formation.