Abstract: The microstructure transformation in the impacted worn surface layer of austenite bainite steel with nodular eutectics(abbreviated as ABNE steel) was investigated with a transmission electron microscope and MDL wear tester. Amorphous structure and nano sized grain in the impacted worn surface layer and dislocation, twin crystal, strain martensite, and deformed bainite structure in the subsurface layer were observed.As the result, the hardness of worn surface increased gradually from the subsurface layer to the worn surface of steel and distributed gradiently, which effectively resisted the impacting and drilling of the abrasive. The dislocation, twin crystal, strain martensite and deformed bainite structure in the subsurface layer having good matching of strengthening and toughening could act to avoid the production of microcracks.This contributed to the good impact wear resistance of ABNE steel.