The Kosudong-gul Cave at kosu-ri, Daegang-myon, Danyang-gun, Chung Chong Bug-do, Province was surveryed by this author on the 3rd of Nov. 1973, 6th of Jan. 1974, 30th of Aug. and 13th of Sept. 1975 through over several times field trips. Yoechon-gul Cave at Yoechon-ri, Gagok-myon, Danyang-gun, Chung Chong Bug-do, Province was surveyed by this author on the 30th of August, 1975. The enviromental factors of both caves checked the siftations for air temperature, water temperature, moisture and pH, as well as the faunae f both caves and ecollogically studieel them. Kosudong-gul Cave (1) The environmental factors checked was the same as table 1. (2) The fauna is 5 classes and 18 species and they classified as Troglobite......2 species-11.1％, troglophile.....5 species-27.7％, and trogloxene....11 species.-61.2％. Yochon-gul Cave (1)The environmental factor Checked was the same as table 2. (2) The fauna is 5 classes and 8 species and they classified as troglobite......1 species-11.1％, troglobite....4 species-44.4％ and trogloxene.....4 species-44.4%.