The genetic fingerprinting of the introduced stock of Sarotherodon melanotheron in China was analyzed using AFLP technique. A total of 247 fragments were detected in the 25 samples using eight primer pairs, the number of fragments produced by each pair of primers were 27 -34, the average fragments was 30.9, the average polymorphic loci of this stock were 16.6%. 25 genotypes were found with each sample owning one genotype. The genetic similarities of the introduced stock of S. melanotheron varied form 0.925 to 0. 995. These results could be served as genetic base for its management and conversation.