Abstract: To identify the difference degree of four new strains of sorghum-sudangrass with low hydrocyanic acid content SLCN-11,SLCN-12,SLCN-13 and SLCN-14,and their parents at a DNA level,we conducted SSR analyses using the variety Mengnong Qingsi No.3 as a control. A total of 12 SSR primer pairs with high polymorphism and good reproducibility were screened from 200 developed sorghum SSR primer pairs. The 10 materials were analyzed using these SSR primers. A total of 509 polymorphic loci were amplified,and the percentage of polymorphic loci was up to 87.30%. Each SSR polymorphic primer pairs could amplify clear and stable bands,which can be used as molecular basis for identifying the four new strains of sorghum-sudangrass. Genetic distance (GD) among 10 materials ranged from 0.3165-0.6692,with an average of using 0.5359; Using the GD value of 0.50 as a threshold,the 10 materials can be clustered into five groups: Mengnong qingsi No.3,loose spike sorghum,SLCN-11,SLCN-12 and SLCN-13; SLCN-14 and brown hull sudangrass; white hull sudangrass; black hull sudangras; red hull sudangrass. This study laid the groundwork for the next step breeding,registration and utilization of new sorghum-sudangrass varieties with low hydrocyanic acid content.