To detect authenticity and species of 23 suspected shark fin samples. DNAs from either shark fin or shark fin derived soup were extracted, and then 12S rRNA gene of mitochondrial DNA that was special for animal species identification was amplified. PCR product was sequenced and homology comparison was deployed by BLAST search in GenBank database with related species sequences. The results showed that, among a total of 23 suspected shark fin samples, 18 soup-sourced, two vermicelli-like, and a fin-like one were failed to extract DNA or amplify target fragments, while the remaining two samples were successful to extract genome DNA and amplify the corresponding 12S rRNA gene fragments. Sequence analysis indicated nucleotide sequences of the 12S rRNA gene fragment from the two samples matched 99% identity to Carcharhinus limbatus and Rhizoprionodon terraenovae, respectively. For those samples containing shark components, high temperature soaking treatment was carried out. High temperature soaking treatment showed gelatin was precipitated in a sample (22#).These results indicated 12S rRNA gene sequence determination could accurately and quickly identify whether the samples contained shark ingredients. If combined with the high temperature soaking treatment to observe whether there was a gelatin precipitation, we can comprehensively judge the authenticity of shark's fin.