Surface modification of PPS was performed by ion implantation, and the influence on the surface property and friction-wear properties were investigated. As a result, new bond such as C-N and C=C were formed in PPS. And the hardness of the specimen went up. Moreover, the friction coefficient decreased as compared with that of un-implanted PPS. And the wear volume was decreased by ion implantation. But when there were many amounts of implanted ion, it increased. Also in any, it turns out that the amount of implanted ion is very important. From the above result, the usefulness of the ion implantation to PPS became clear.