Abstract: Using 5 pairs of SSR primers, the genetic diversity of 52 hybrid clones of Aspen is detected. The result shows that percentage of polymorphic loci is 100% in five loci studied, in which the average number of alleles is 4.4, the locus PTR7 is the greatest amount in effective alleles, and the locus PTR12 is the least. Besides, there is the highest genetic diversity among the clones of Populus tremula×P.tremuloides, and the lowest variation in that of P.davidiana×P.tremuloides; By cluster analysis on the basis of genetic distance, it demonstrates that hybrid of P.tremula×P.tremuloides and P.tremula are firstly clustered, and then hybrid of P.davidiana×P.tremuloides, P.davidiana are finally clustered. This study demonstrates that hybrid clones of Populus tremula×P.tremuloides from Fenland have higher genetic diversity than the other Aspen clones, what is very important to enlarge genetic sources, cross breeding and heterosis utilization of this species in the future.

Key words: simple sequence repeat DNA (SSR), aspen hybrid, genetic diversity