At present it is lack of the ecological data about corsac forx(Vulpes corsac)in China.Nine non-breeding corsac fox’dens were dug and measured in Hulunbeier grassland in Inner Mongolia, of which six have one tunnel and one entrance for their own and another three have two tunnels and two entrances for each. The mean width of den entrance is 27.3 cm and the mean height of entrance is 22.7 cm. The mean length of the dens is 207.3 cm and the mean distance is 54.7 cm from the ground to the deepest point of the dens. Although corsac fox used to expand rodent’s dens as its own dens, which is the main source of the dens, sometimes it digs dens by itself too. Corsac fox’ dens are very narrow and long corresponding with its stature. In the measured twelve dens’ tunnels, there are nine with a bend. Corsac fox’dens are generally distributed in open grasslands, riverine gentle incline or steep hills.
The selection of dens of Vulpes corsac% was investigated at Xinbaerhu Youqi in Inner Mongolia Autonomous Region, China. The result showed that the main factors notably influence on den habitats of %V. corsac% were human disturbance and water resource. The table of frequency and dentrogram indicated that the suitable habitat of %V. corsac’s% dens was: the flat grassland, hillside, and small hills with the distance from the water ≤1 000 m, from the human disturbance ≥1 000 m. the main resource of %V. corsac% is the scrap dens of %Marmola bobak.%