A soil classification scheme for field use introduced by C. C. Nikiforoff, based on the genetic concept is described: The members of the highest category in this scheme are the recognized genetic soil zones of the world. The natural divisions of a soil zone into physiographic regions constitute the soil Combinations. In a Combination, soils are developed on different parent materials. The soils found together on each-parent material form soil Associations within the Combination. The Soil Associates of each Association are distinguished by the morphological features expressed within the soil profile which are acquired by reason of position and drainage. 3 chief types of Associates are recognized: (1) locally arid (Oromorphic) associate, (2) normal (Phyto-morphic) associate, and (3) locally humid (Hydro-morphic) associate. Variations or modifications of a soil associate are mapped as phases. The phytomorphic associates of all the associations together determine the soil zone. The use of this scheme enables the soil surveyor to classify not only the normal soils, but also to classify in a logical manner every soil as it occurs in the field.