Adsorptive removal of aqueous humic acid (HA) with aminopropyl functionalized silica coated Fe3O4 nanoparticles was investigated. The adsorption isotherm of HA can be described very well by both the Langmuir and Freundlich models and the theoretical maximum adsorption capacity was 181.82 mg/g. Adsorption kinetics followed both the diffusion-controlled and the attachment-controlled process. HA adsorption increased monotonously with increasing solution pH. The presence of cations in solution, results in augmented HA adsorption. The adsorbent exhibits excellent desorption and regeneration properties. Zeta potential and XPS analysis reveal that electrostatic interaction and surface complexation between protonated amino groups and the disassociated HA molecules are the main adsorption mechanism.