In this research, the GO/Fe3O4 nanocomposite (GFO) on activated carbon (AC) was used to adsorption arsenic As(V) in water. AC was added to the co-precipitation process to synthesize GO/Fe3O4/AC material with a GFO:AC ratio of 1:1 to reduce product costs. The composition, morphology, and bonding of synthesized nanomaterial was analyzed by XRD, FESEM, Raman; indicating that the Fe3O4 nanoparticles in the average crystal size of 11 nm were uniformly distributed on the surface of AC and GO sheets. In addition, the specific surface area shown by the BET result in a value of 708 m2/g. The As(V) adsorption capacity of GO/Fe3O4/AC nanocomposite was analyzed by AAS method at different pH values. Result showed that the maximum As(V) adsorption efficiency of material sample was 98% and the adsorption capacity reached 14.74 mg/g in 60 min at pH = 6. Accordingly, GO/Fe3O4/AC could be used as an effective adsorbent for the removal of arsenic from aqueous solutions.