Graphene oxide/polyamidoamines dendrimers (GO/PAMAMs) composites were synthesized via modifying GOwith 2.0 G PAMAM. The adsorption behavior of the GO/PAMAMs for acid Bordeaux B (ABB) was studied and the effects of media pH, adsorption time and initial ABB concentration on adsorption capacity of the adsorbent were investigated. The optimum pH value of the adsorption of ABB onto GO/PAMAMswas 2.5. Themaximumadsorption capacity increased from325.78 to 520.83mg/gwith the increase in temperature from298 to 328 K. The equilibriumdata followed the Langmuir isothermmodel better than the Freundlich model. The kinetic study illustrated that the adsorption of ABB onto GO/PAMAMs fit the pseudo-second-order model. The thermodynamic parameters indicated that the adsorption process was physisorption, and also an endothermic and spontaneous process.