Abstract: In order to explore effects of different humus components on loss of adsorptive ammonia-nitrogen, characteristics of the enrichment of ammonia-nitrogen by different organo–mineral complexes, components of humus were investigated through a batch experiment of equilibrium adsorption. Results indicate that in terms of ammonia-nitrogenenrichment coefficient, the organo-kaolinite complexes in humus displayed an order of humic acid–Kaolinite > humin–Kaolinite > fulvic acid –Kaolinite, being 1.26, 1.14 and 1.01, respectively; and the organo-Montmorillonite complexes did an order of humic acid–Montmorillonite > humin–Montmorillonite > fulvic acid–Montmorillonite, being 1.22, 1.13 and 1.03, respectively. The adsorption of filling of ammonia-nitrogen into pores existing in the glassy colloids cementing humic acids and humin, rated as hard carbon, is the major cause leading to higher ammonia-nitrogen enrichment coefficient of humic and fulvic acids-mineral complexes.