Abstract: The mitochondrial DNAs (mtDNAs) from slow loris (Nycticebus coucang bengalensis) and tree shrew (Tupaia belangeri chinensis) liver were digested with ten restriction endonucleases.One site for BglⅠ,HindⅢ,PstⅠ,SalⅠ,XhoⅠ;two sites for EcoRⅠ,BglⅡ,PvuⅡ;and three sites for BamHⅠ,EcoRⅤ were found on the mtDNA from slow loris.One site for BglⅡ,HindⅢ,PstⅠ,SalⅠ,XhoⅠ;two sites for BamHⅠ,BglⅠ,PvuⅡ;three sites for EcoRⅠ;and four sites for EcoRⅤ were found on the mtDNA from tree shrew.The mtDNAs were also cleaved by double-enzyme digestions with the above mentioned enzymes.The fragments thus obtained and their molecular weights were estimated by agarose gel electrophoresis.Restriction maps for slow loris and tree shrew were made according to the number and the size of those fragments obtained by single and double digestions.The distribution of cleavage sites were found not to be random.