In order to elaborate the genetic diversity of the major barley varieties planted in China and their resistance origins to spot blotch caused by Cochliobolus sativus, the coefficient of parentage (COP) was utilized to cluster 155 major barley cultivars with their pedigree information, meanwhile 79 varieties of them were inoculated with 2 strains of high virulence at both seedling and adult-plant stages. Based on the results, the 155 major barley varieties were clustered into 6 families, and 14.77 % of them possess genetic relationships with each other. There are 1763 variety combinations found with genetic relationships among the total 11935 ones, and the COP values range from 0.0000 to 0.7500, its average COP value is 0.0132. According to the pedigree analysis, the core parents for those varieties developed by different breeding institutes were identified and their possible primary parents were also deduced. In addition, most of the tested cultivars were susceptible to spot blotch in seedling and adult-plant stages. Among them, several varieties in the series of Kenpimai ones and Mengpimai No.3were identified to be highly resistant to spot blotch, and a few varieties of series of Huadamai and Zhudamai showed moderate seedling or adult-plant resistance. The results of pedigree analysis and resistance characterization of spot blotch revealed that the resistant genes utilized in the barley varieties in China may derive from different genetic backgrounds. The analyses will promote the efficiency of resistant genes selection, minimize barley accessions to be screened and accelerate the progress of exploitation and utilization of new spot blot resistance genes germplasm.