The samples derived from the Chinese vessels were collected from 7 locations of central Pacific Ocean waters (16°S-8°N;160°W-155°E)from September 2011 to January 2012.By using 585 bp fragments of mtDNA control region, we analyzed the sequence variations and genetic structures of 101 samples collected from 7 locations.In total, 23 variable sites were acquired, and 80 haplotypes were identified.Analysis of mtDNA D-Loop gene sequences from 7 localities revealed that the mean haplotypic diversity and nucleotide diversity was 0.994±0.002 and 0.00892±0.00038, respectively.The AMOVA tests revealed that 98.18% of the genetic variation occurred within populations.F_st analysis suggested that no significant genetic differentiations were found within the 7 localities.Neutrality test and the mismatch distribution indicated a recent population expansion that occurred about 3 350 000-5 440 000 years ago, suggesting a frequency genetic exchange and a poor genetic structure.A single population and a low genetic diversity call for a responsible and effective management to ensure the sustainable development of yellowfin tuna.