Abstract:Perennial ryegrass is clearly one of the most important and widely used forage and turf grasses,exhibiting rapid establishment,good tillering ability and high acceptability to livestock.The genetic relationship of 16 ryegrass cultivars,including 2 accessions annual cultivars and 14 entries perennial cultivars,from different breeding company were analyzed using 61 RAPD markers,the morphological characters were also observed.61 RAPD primers generated 408 bands,of which 367 bands (89.95%) were polymorphism;It showed that the genetic polymorphism in these cultivars was low,the coefficient among the cultivars fell between 44.55%95.69%.Dendrogram obtained using these molecular markers is not in agreement with their separated morphologic character.High correlation was not observed between the two annual ryegrass cultivars.