Abstract: The genetic diversity and identification of citrus germplasm resources and its mutants was evaluated by Randomly Amplified Polymorphic DNA（RAPD）technique. Ten of seventy random primer and several mixed primers could produce 142 bands, 72 of which were polymorphic. 6.8 polymorphic bands were displayed by every single primer and 1.3 polymorphic bands by every mixed primer. Cluster analysis showed that similarity coefficient between 0.834 and 0.960 of these 25 genotypes by UPGMA（un-weighted pair group method with arithmetic）analysis. And based on those data, the dendrogram of these genotypes was constructed. The results revealed RAPD marker is suitable for identify sports from its original strains, 25 citrus resources indicate 25 genotypes. The high similarity coefficient showed that there is narrow genetic background among citrus resources in the experiment.