Endophytic bacterial diversity in rice plant cultivated on acid sulphate  soil  of  the  Mekong  Delta,  Vietnam  was  studied.  Rice  plant  samples  were  taken  in  four  regions  (Trung  Song  Hau,  Tu  Giac  Long  Xuyen, Dong  Thap  Muoi  and  Ban  dao  Ca  Mau).  Endophytic  bacteria  were  isolated in two kinds of medium (LGI, NFb) together with 16S rRNA gene  fragments  amplified  from  DNA  using  eubacterial  universal primers  (p515FPL,  p13B  and  PCR-1).  A  total  of  160  isolates  were isolated on two media and all of them have ability of nitro gen fixation and phosphate solubilization together with IAA biosynthesis but there were  60  isolates  having  the  best  characteristics  and  they  were identified as rice endophytes. The sequences from selected endophytic bacteria  (15/60  isolates)  showed  high  degrees  of  similarity  to  those  of  the  GenBank  references strains (between 98% and 100%). From  15  isolates,  3  isolates belonged to  genus Bacillus  (20%),  12  isolates were Proteobacteria (80%)  with Beta and Gammaproteobacteria  were 5 isolates (33%) and 7 isolates (47%), respectively . From these results showed that  4 Burkholderia vietnamiensis  strains (Burkholderia vietnamiensis  HG6-21b, KG2-21, BL1-21b and LA5-22b)  from 4 regions (Trung Song Hau, Tu Giac Long Xuyen, Ban dao Ca Mau and Dong Thap Muoi)  revealed promising candidates with multiple beneficial characteristics and they have the potential for application as inoculants or bio-fertilizer adapted to  acid sulphate soil and high-yielding rice because they are not only famous strains but also are safety strains for agricultural sustainable.