The high hydrophobic magnetic montmorillonite (MMT) nanoparticles were synthesized in two solvents (deionized water and ethanol) by using octadecyl trimethylammonium bromide (OTAB) as intercalating agent and Fe3O4 as magnetic nanoparticles. The obtained samples were characterized by FTIR, XRD, EDS, SEM, VSM. When Fe3O4 was loaded before OTAB on MMT, the sample prepared in deionized water exhibited better adsorption than that prepared in ethanol. The order of Fe3O4 and CTAB introduction had great effect on the hydrophobicity, magnetism, and adsorption. Compared with OTABMMT-Fe3O4, Fe3O4-MMT-OTAB possessed higher hydrophobicity and higher magnetic response. The contact angle of Fe3O4-MMT-OTAB could reach 84.80 degrees and Fe3O4-MMT-OTAB possessed higher M-s (9.25 emu/g) than OTAB-MMT-Fe3O4 (632 emu/g) dose. Fe3O4-MMT-OTAB will become a promising candidate of anisotropic nano-filled powder in polymers by using low magnetic field to obtain the orientation, based on its above excellent properties. (C) 2017 Elsevier B.V. All rights reserved.