<正>Objective: To investigate the mitochondrial DNA sequence polymorphism in Chinese Dongxiang ethnic group and to provide basic data used in ethnic origin investigation and forensic purpose. Methods: Genomic DNA was extracted from the whole blood of 100 unrelated individuals of Chinese Dongxiang ethnic group by standard Chelex-100 method. The sequence polymorphism was determined by PCR amplification and direct sequencing. Results: Eighty-two polymorphic sites were identified in mtDNA D-loop region 16 091 - 16 418 np

and 88 haplotypes were found. The genetic diversity was calculated to he 0.9969

and the genetic identity was 0.013 2. Conclusion: There are some particular polymorphic sites in Chinese Dongxiang ethnic group

and these sites provide an important basis to investigate the origin of Dongxiang and the relationship between Dongxiang and other ethnic groups. The result also suggested that sequence polymorphism from 16 091 -16 418 np in human mitochondrial DNA control region can be an useful tool for