A novel fullerene-maleic anhydride copolymer is synthesized via radical polymerization. It is soluble in polar solvents such as water, dimethyl sulfoxide, tetrahydrofuran, and so forth. The product is characterized by FTIR, UV-visible, and GPC. Transmission electron microscope analysis shows that it presents an ideal spherical shape in water with an average particle diameter of about 36 nm. Four-ball tests show that the addition of a certain concentration of the fullerene copolymer to the base stock (2 wt% triethanolamine and 0.5 wt % Alkylpolyoxyalkylene Phosphate Zinc (OPZ) aqueous solution) can effectively raise the load-carrying capacity (P, value) and raise the antiwear ability. (c) 2005 Wiley Periodicals, Inc.