Abstract: Amplified fragment length polymorphism（AFLP）makers were used to analyze the genetic diversity and genetic differentiation in eight populations of Hyphantria cunea. The results showed that five primers used in this study produced 548 polymorphic loci out of 564 loci totally. The percentage of polymorphic loci（P）was 97.16% and Neis gene diversity（h）was 0.291 0, indicating high genetic diversity in H. cunea. Analysis of molecular variance（AMOVA）revealed that a high proportion（68.95%）of the total genetic variation was partitioned among populations, suggesting significant genetic differentiations among the eight populations of H. cunea. Gene differentiation coefficient（Fst）among populations was 0.310 5. Average genetic similarity of the eight populations was 0.892 7, while average genetic distance was 0.114 7. Eight populations were clustered into four groups in unweighted pairgroup mean analysis（UPGMA）. The relationship between the genetic diversity and the mechanism of its environmental adaptation and population expansion was further discussed.