The efficiency of the flocculation of humic compounds and their derivatives with chitosan was studied as a function of pH, concentrations of chitosan and dissolved humic compounds, and also the presence of inorganic coagulants. Samples of humic compounds were studied by the methods of potentiometric titration and gel permeation chromatography. The molecular weight distributions and the spectra of ionization constants of their functional groups were calculated. The flocculation efficiency of chitosan with respect to humic compounds is much higher than that of polyacrylamide.