Moulins are powerful evidence for glacial development as well as a historic witness to paleo-climatic and paleoenvironmental shifts. Available data indicate that most moulins are developed on the bottom of glacial valleys and glacial beds and that they are small in size and limited in number. But the moulin swarms discovered in the medium-low mountains areas of Hebei and Inner Mongolia are mostly distributed on the mountain crests and peaks of hard granites. Moulins of five moulin swarms discovered and investigated on the spot now amount to more than 400~500, which are distributed at elevations of ca. 650~1500 m above sea level. These moulins are generally 0. 5~2 m in diameter and 0. 2-1 m or so in depth. The largest moulin is about 10 m wide and about 3. 5 m deep, whereas the mouth width and depth of the smallest moulin are both about a few centimeters; the deepest moulin is about 5 m in depth with a mouth width of only 0. 12 m. Most moulins are round, elliptical or irregular in shape with a small mouth, a large belly and a flat bottom. The discovery of large numbers of moulin swarms in the medium-low mountains areas of Hebei and Inner Mongolia provides evidence that large-scale glaciation did took place in the early Quaternary in medium-low mountains areas of eastern China. This discovery provides very important grounds for the study of the global paleoclimatic and paleoenvironmental evolution and also has great significance for the tourist resources and economic development.