The investigation of terrestrial mollusk in Baishuijiang National Nature Reserve in Gansu Province was carried out in 2005-2006.A total of 62 species or subspecies belonging to 12 families and 26 genera or subgenera had been obtained.The species of Oriental realm occupied absoluteness predominance and accounted for 85％of the total.The most abundant species diversity of terrestrial mollusks occurred along the altitudinal gradient of 600-1 200 m.Species number reduced greatly over 1 600 m.Terrestrial mollusks distributed on slope wasteland or shrub more than in the forest or farmland.