Abstract: A methods for direct-sequencing by Tag DNA polymerase has been developed Using this method, nucleotide sequences of major hypervariable region of human mtDNA from 100 unrelated Chinese Han population have been determined. The sequences all include a 328bp (from 16091 to 16418 site)fragment in D-loop-forming region. By comparison of the sequences, 86 mtDNA types were observed among these 100 individuals, the highest frequency among them was 7％. 81 variable sites were found. The probability of two unrelated individuals of Chinese Han population having same sequence in the sequencing seament of D-loop region is 0.0068. Our data showed that mtDNA is maternally inherited in 4 generations of 2 families and 3 generations of5 families and 2 generations of 10 families.

Key words: mtDNA. D-loop. PCR. nucleotide sequence.