The purpose of this study was to evaluate the possibility of using Cytochrome c oxidase 1 (COI) for identifying the animal species. Three samples are kept at the Vietnam National Museum .of Nature (VNMN) with its code of GN.bttnvn, GC.bttnvn, BHM.bttnvn, which were initially morphological identified. These samples were named Asian Black bear (Ursus thibetanus), Sun bear (Helarctos malayanusor synonym Ursus malayanus and Leopards (Panthera pardus). DNA was isolated from muscle tissue of samples, then proceeded by PCR. PCR products were purified by Qiagen Gel Extraction kit and then sequencedly. identified by using primers Barcode LCOI 490/HCO2 198 of the DNA Barcording program. The result of COI gene segment was amplified, of which its size was 623 bp for both the Black bear and Sun bear and it was 653 bp for the Leopard. Computerized Mega software version 5.2.2 and BLAST program were then used for analyzing and reconciled with data from international gene banks, which shown that the specimens of Black bear, Sup bear and Leopard were named exactly as intended by morphological method. This results that the studied samples of GN.bttnvn, GC.bttnvn, BHM.bttnvn have been successfully registered at the Genbank with public atmounced codes of KF98648I, KF986482 and KF986483 respectively. The similarity degree the sequences from taken samples of Asiatic black bear, Sun bear and Leopard compared with data published in Genbank are. 99 percent, 99.5 percent and 99.85 percent respectively. With the results obtained, the COI gene segment can be used for identifying samples of rare animals which are not properly intact.