Abstract: The over-segmentation or incomplete segmentation may happen when using Normalized Cut（N-Cut） to segment images.This paper proposes an improved algorithm based on the result of N-Cut using classic merge and split method：merge some segments with similar color and texture；split some segments further.Experimental results validate the effects on color natural images by this algorithm，which not only keep the advantages of N-Cut，but solve the problem of over-and incomplete segmentation as well.