It seems to be possible to evaluate chemical stabilization of organic wastes on the basis of various humification indexes determined in the laboratory, i.e., a place in which controls can be applied more rigorously than in the field. Among the parameters tested, the HI seems to be the most appropriate, even though it is less simple and rapid. Before defining which among the parameters is the most suitable for evaluating the degree of maturity of organic wastes and utility in crop production, a much greater number of wastes of the same kind but composed under different conditions must be tested. Among the chemical criteria required for the characterization of an organic waste stabilization product (e. g. , compost), humus content and quality rank high. This aspect was investigated by several authors each following a different experimental approach. The objectives of the present study were to attempt to follow the course of the maturation process in composting through the use of various humification parameters; and to evaluate suitability of the parameters for statistically assessing the maturity of different organic wastes.