Abstract: An efficient approach is proposed to find a non dominated set Two techniques are employed to speed up the search for non dominated set One of them is that the search for a non dominated set is from an integer set corresponding to the original set, instead of the original set The other is that the likely non dominated elements stay at the front in the check sequence, and the non dominance is checked with as few comparisons as possible, and once the rest check sequence is dominated, the search is stopped Theoretical analysis and experimental results show that the new approach performs much better than other approaches when the original set has a larger non dominated set