The weed resistance has become the major factor restricting crop production, and the mechanism of weed resistance is divided into target resistance (TSR) and nontarget resistance (NTSR). Target resistance includes target gene mutation and target gene overexpression, in which target gene mutation is the main factor. Non-target resistance is caused by the reduced absorption and conduction of weed to herbicide, the shielding and isolation, and the enhanced detoxification ability of weed to herbicide, in which the enhancement of weed metabolism is the primary reason. In this paper, the research progress on weed resistance to acetohydroxyacid synthase (AHAS) inhibitors was reviewed from the aspects of weed resistance, target resistance, effects of AHAS mutation on structure and function, non-target resistance and suitability of resistant weeds.