The remarkable antiquity,diversity,and significance in the ecology and evolution of Cetartiodactyla have inspired numerous attempts to resolve their phylogenetic relationships.However,previous analyses based on limited samples of nuclear genes or mitochondrial DNA sequences have generated results that were either inconsistent with one another or weakly supported,or highly sensitive to analytical conditions.Here we presented strongly supported results based upon over 1.3 Mb of aligned DNA sequence matrix from 110 single-copy nuclear protein-coding genes of 20 Cetartiodactyla species which represented major Cetartiodactyla lineages,plus three species of Perissodactyla and Carnivora as outgroups.