Abstract: The toughening modification of nylon 6 with POE-g-MAH as an impact modifier was conducted, and the effect of POE-g-MAH content on the mechanical properties and flowability of nylon 6/POE-g-MAH compounds was investigated. Most of all, the impact toughness of the compounds at normal and low temperatures as well as under an extremely cold condition were studied intensively. The microstructure of compounds was further characterized by SEM. The experimental results indicated that the compound with 20 wt % of POE-g-MAH exhibited optimium mechanical performance and good impact toughness at low temperatures. Even at an extreme low temperature of -50 °C, the compounds containing 20 and 30 wt % of POE-g-MAH still kept good toughness. Compared to pure nylon 6, and the impact strength increased by 130% and 350%, and the elongation at break was improved by 195% and 230%. Moreover, the low-temperature tensile strength also increased with a decrease of temperature.