SRAP was used to analyse the genetic relationships of 42 Cymbidium grandiflorium cultivars from Different countries ,and 4 species of native Cymbidium. 29 Stable and polymorphic primers were screened from 34 primers,and a total of 398 DNA bands were amplified,387 of which were polymorphic, The ratio of polymorphic bands was 97.2%.The average number of polymorphic DNA bands amplified by each primer was 13.3.The genetic similarity among 46 Germplasm ranged from 0.41～0.99 ,with an average of 0.60 .According to the amplification of 29 markers, genetic similarity coefficient of Dice was Calculated using software NTSYS 2.10e,and a dendrogram of genetic relationship was constructed using UPGMA method .The dendrogram showed that all the tested cultivars and species were classified into four cluster groups with the similarity coeficient of 0.60,and well revealed the Genetic Diversity and Genetic Relatives among Cymbidium grandiflorium cultivars and native species. The findings of this research would provide a scientific basis for Cymbidium grandifloriu germplasm utilization,and parental selection in cross breeding.