He special merits of Z.A. Waksman and I.V. Turin are marked in the development of soil humus and organic matter theory. Little-known pages ex vivo of these outstanding experimentalist scientists, founders of two schools and acknowledged leaders in the investigation of the soil organic matter, are presented in the article. A comparative analysis of theories by I.V. Turin and Z.A. Waksman on the origins, composition and properties of the soil organic matter is given. Actual conceptions, ways and methods of the organic matter fractioning are described in the work. The alternative points of view on the humine matters of soils by I. V. Turin and Z. A. Waksman are considered. A brief review on the heteropolymeric and supramolecular models of soil humic matter composition is presented.