MtDNA RFLP and PCR-RFLP techniques were used to reveal polymorphism between Siberian tiger (Panthera tigris altaica) and  South  China  tiger (Panthera tigris amoyensis).  In mtDNA RFLP study,  mitochondrial DNA was extracted from liver, kidney and heart tissues  of Siberian tiger  and South China tiger  and  purified. Restriction  endonuclease  fragment patterns of mtDNA were digested with 20 enzymes recognized 6-bp. Only 1 (XbaⅠ) out  of  20  restriction  enzymes  revealed  polymorphic fragments.  The restriction pattern generated by 19 of the enzymes in  Siberian  tiger were identical with that  in  South  China  tiger. In PCR-RFLP study, D-loop was amplified and 8 endonucleases recognized 4-bp were used to digest PCR product, 1 out of 8 endonucleases (RsaⅠ)  revealed polymorphic fragments.  Genetic  distance between Siberian tiger and South China tiger  calculated based on the two results was very small.  This  is  probably  due  to  the  following  factors: there was no natural barrier between the two  subspecies; they have strong dispersal ability and were separated only  within  several  hundred years.