Organic compounds likely to be present in composts organic waste in municipal waste can be subdivided into five main classes: plant waste, kitchen waste of vegetable or animal origin, paper and cardboard, plastics, undesirable high in carbon and sludge from water treatment. A large variety of organic compounds constitute this initial waste in varying proportions. This review highlights the evolution of the characteristics of organic matter during the compositing of different materials obtained from techniques derived from the study of soil organic matter. Biochemical fractionation of organic matter and spectral analysis revealed the significant degradation of cellulose and hemicellulose throughout composting. On the other hand, the slow degradation of lignin which is more resistant to biodegradation leads to its concentration in the organic matter. Since soluble compounds (mainly simple sugars and proteins) may be of microbial origin, they are present in composting. During composting, the characteristics of organic matter become increasingly independent from the origin of the waste.