In six geogr aphical populat ions of Carassius auratus gibelio , the ND 5/6 r egion (approximately 2 .5Kb)of mtDNA genome have been amplif ied by the polymerase ch ain reaction (PCR), and the pr oducts were examined using rest rict ion fr agment length polymor phism (RFLP).11 elect rophoresis patterns and 7 haplotypes (genotypes)have been observed .Based on the genet ic distances , the UPG molecular phylogenet ic tr ee of the populat ions was constructed .The results indicate th at the six popula tions of the C .auratus gibelio can be imcorporated into four populat ions , namely , the Heilongjiang and Anhui , the Henan , the Yunnan and Guizhou , and the Jiangxi .The first is the closest to the third . The He nan is much closer to the Heilongjiang and Anhui .The far thest is between the Jiangxi and the other populat ions .