Abstract: The AFLP genotyping about 38 Aeromonas veronii isolates and an Aeromonas veronii standard strain was conducted by synthetic universal joints and adapters which matched the specific primers. The results showed that the 39 strains of Aeromonas veronii augmentation were out 1080 visible strips by five selected primers. The lengths of the segments ranged from 50 to 1000 bp. Seven hundred and twenty seven of the total strips were polymorphism. Each primer combinations produced 154 bands in average. Average detection rate for polymorphism was 66.7%. By UPGMA method to strip the clustering analysis, a clustering branches tree, Aeromonas veronii was obviously divided into nine classes. The fourth group Ⅳ type contains genes 14 strains isolated, accounted for about 35.9% of the total bacterial count, distributed in five different areas. Presumably, it may be the major epidemic genotype of case disease to channel catfish. Aeromonas veronii had regional differences. And Aeromonas veronii in the same area showed genotype diversity.