14 major maize cultivars in Liaoning Province of China were analyzed for their endophytic bacteria population studies. The results showed that Bucillus ssp was the major genera of endophytic bacteria strains isolated from the maize roots, and the minor strains include Enterobacter spp., Serratia spp., Xanthomonas spp., and Clavibacter spp. Also, there were degrees of variations between endophytic bacteria isolated from different species of maize cultivars and growth periods. All 14 major maize cultivars were subjected to a random amplified polymorphic DNAs (RAPDs) study, among 90 random primers tested, 13 primers were able to generate distinct DNA fragments, in which, 72.7% of 139 RAPD fragments were shown results of polymorphism. Furthermore, from the studies of SPSS cluster analysis which conducted on maize cultivars and endophytic bacteria, our results strongly suggest a close relationship between the species and numbers of endophytic bacteria and the genetic background of maize cultivars