Anthraquinone/graphene nanocomposite was synthesized via a facile two-step electroreduction process and was characterized with various techniques. The electrocatalytic activity of the as-prepared anthraquinone/graphene nanocomposite towards O2 reduction was studied in neutral medium. Results show that most of oxygen-containing functional groups on graphene oxide were removed after electroreduction. Anthraquinone/graphene nanocomposite exhibits excellent electrocatalytic performance for two-electron reduction of oxygen, suggesting its potential as metal-free electrocatalysts for oxygen reduction reaction.