Abstract: PTW (Potassium titanate whiskers) reinforced  monomer casting（MC）nylon composites were prepared by anionic polymerization of caprolactam for improving the ability of train plates’ gasket affected by absorbing moisture to get a high and steady friction coefficient beside better toughness and intensity，and treated by boiled water. The tribological properties of the composites were investigated by a ring-blank wear tester under dry condition. Compared with the samples treated by boiled water，the friction coefficient of the untreated sample becomes instable because of the moisture absorbing ability，while the treated one could get stability in a short time. The main wear mechanism of the pure nylon is adhesive，and the PTW reinforced MC nylon reduces the adhesive wear obviously. The total mass wear ratio of the pure sample is higher than that of the reinforced one. The moisture absorbing ability cannot affect the wear mechanism obviously. The PTW reinforced monomer casting nylon treated by boiled water could improve the tribological capability.