PET film was grafted with acrylic acid (AA)/methacrylic acid (MAA) and chelated with lanthanum(III) to impart the antistatic property. Graft yield was dependent upon the monomer ratio of AA/MAA, and the maximum graft yield was obtained at the ratio of 2/8 (AA/MAA). Lanthanum(III) content increased with the increase of chelating temperature, and this behavior varied with monomer ratio (AA/MAA). As the amount of AA increased, the La(III) content increased when the greaft yeild was held constant. Although the maximum graft yield was obtained at the ratio of 2/8 (AA/MAA), the lanthanum content and the static electrical value of PET-g-AA/MAA (2/8) and PET-g-AA/MAA (5/5) to be chelated with La(III) were almost same. It means that La(III)-chelated PET-g-AA/MAA (5/5) is more useful than La(III)-chelated PET-g-AA/MAA (2/8) in the industrial aspect.