A batch system was applied to investigate the behavior of adsorption of methylene blue (MB) and crystal violet (CV) from aqueous solution using a renewable magnetic alginate composite containing graphene oxide (M-GO/ Alg) in single and binary systems. The surface morphology and chemical structure of the adsorbent were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and vibrating sample magnetometer (VSM) analysis. The experimental data were fitted by the isotherm models and adsorption kinetics. And the maximum adsorption quantity of MB and CV reached 459.85 and 69.46mg/g at 298 K for M-GO/ Alg, respectively, as deduced from Langmuir model. After five successive adsorptive removal cycles for both dyes, no significant performance loss was observed for M-GO/Alg. Moreover, M-GO/Alg was easily separated under an external magnetic field. In binary system, MB and CV exhibited competitive adsorption. The obtained results suggested that M-GO/Alg can be used as an eco-friendly and recyclable adsorbent to remove cationic dyes from aqueous solutions.