Magnetic NiFe2O4/SBA-15 nanocomposites were synthesized by a facile impregnation method, and NiFe2O4 nanoparticles presented spinel phase structure and existed in the mesopores of SBA-15. Partial mesopores were blocked by NiFe2O4 nanoparticles and micropores formed, which the capillarity of micropores played a decisive role for methylene blue (MB) adsorption. The saturation magnetization increased from 2.34 emu g(-1) to 10.03 emu g(-1) with the NiFe2O4 content, while the specific surface area decreased from 552.18 m(2) g(-1) to 260.40 m(2) g(-1) and pore volume decreased from 1.13 cm(3) g(-1) to 0.49 cm(3) g(-1). MB adsorption could be improved by optimizing the NiFe2O4 content of the nanocomposites. MB could be adsorbed completely in 60 min with the optimum nanocomposites and could be separated easily from water by magnetic separation technique. (C) 2017 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.