The genetic diversity and genetic relationships among 60 accessions of barley, including 33 Chinese landraces, 19 wild relatives from Tibet and 8 cultivars from other countries, were evaluated by RAPD markers. Totally 119 bands were detected with 32 primers, with the average of 3.72. Eighty-seven polymorphic bands were detected, representing of 73.11% of polymorphic bands (PPB) and 0.434 of mean polymorphism information content (PIC), respectively. The average number of alleles (Ne) was 2.304. One to eight polymorphic bands were generated by each primer. Among 60 barley accessions, the RAPD-based genetic similarity (RAMP-GS) ranged from 0.757 to 0.981, with the mean of 0.871. The mean GS of 19 wild barley accessions, 33 Chinese and 8 foreign cultivars were 0.892,0.879 and 0.882, respectively. UPGMA cluster analysis showed that these accessions could be divided into five groups and the genetic diversity based on RAPD markers was correlated with their geographical distribution.