Abstract: For multi-attribute decision making (MADM) problems with key attributes, a new decision making approach on the base of error-eliminating theory is proposed. Firstly, multi-attribute decision making problem under “one vote negation system” situation is proved the same as multi-attribute decision making problem with key attributes. Secondly, the concepts of non-optimal strategy and non-dominated strategy are given on the basis of error-eliminating theory. Thirdly, non-optimal strategies are excluded from the set of alternative strategies by the way of calculating error values, and the non-dominated strategies are prioritized and selected according to the error deviation degree. The rationality and feasibility of this model will be shown by an illustrative example finally.