This revised publication replaces The Canadian System of Soil Classification (second edition) published in 1987. The changes incorporated in this current publication are based on the work of the Soil Classification Working Group (SCWG) formerly of the Expert Committee on Soil Survey, and continued by the Land Resource Division of the former Centre for Land and Biological Resources Research. Current taxonomic activities are part of the Land Resources Program of the Eastern Cereal and Oilseed Research Centre, Ottawa, Ontario. Highlights of the third edition: A tenth order, Vertisolic, has been added; Subgroups intergrading to the Vertisolic Order have been added in the Chernozemic, Gleysolic, Luvisolic, and Solonetzic Orders; Major revisions have been carried out to the Cryosolic Order; A complete key to soil classification has been added in chapter 3.