Chemical properties of 42 Chilean forest soil profiles, corresponding to 207 samples between 33° and 53° South latitude, are discussed. Water pH and pH-KCl in surface mineral horizons varied from 3.1 to 6.6 and from 3.2 to 5.9 respectively. The most acidic soils were located in the southern latitudes. Humus was accumulated on soil surface and decreased markedly with depth. C/N relationships indicated an increase of humus evolution with profile depth. Fulvic acid/humic acid relationships increased with depth. CEC, exchangeable cations, and fertility were strongly dominated by organic colloids. Al and Fe forms indicated a descending movement or Al- and Fe- organic complexes in some soils.