Objective     To explore the features of the cytochrome c oxidase subunit Ⅰ (COXⅠ) of Asian black bear Sichuan subspecies.      Methods     Primers were designed according published gene sequences of other bear species. A DNA sequence was amplified by PCR from the bear Sichuan subspecies’s hair-follicle tissue total DNA

then the PCR product was sequenced. The results were analyzed and a forecast analysis was carried on.      Results     The amplified COXⅠ gene of Sichuan black bear was 1 605 bp and contained a 1545-nucleotide open readin

g frame encoding 514 amino acid residues. The overall base composition of COXⅠ gene is 26.9 %

23.1%

18.3 %

and 31.8 % respectively to A

C

G

and T. The start codon of the COXⅠ is ATG

while the termination codon TAA. The protein’s pI is 6.29 and     weight is 57.2×10

3

. The similarity analysis and phylogenetic tree analysis indicated that Sichuan black bear has closer relationship to American black bear

but not to brown bear and polar bear. Among dogs

caws and rats

it is closer to the former one.      Conclusion     There are high similarities in the DNA sequence

protein amino acid sequence of Asian black bear Sichuan subspecies with other bear species

indicating a high conservativity of COXⅠ in these involved species.