Abstract: It was reported that the population structure and the succession of bacteria was related to the rate of bioleaching.In order to investigate the relationship in the bioleaching system of the low-grade nickel sulfide ore and then improve the rate,DGGE (denaturing gradient gel electrophoresis) and 16S rRNA gene sequence analysis are used to analyze the bacterial population structure in the leaching system in the shake-flask leaching culture.The results show that the main bacteria population in the bioleaching system is acidophilic Thiobacillus and three bands are found by DGGE analysis.The change of DGGE bands indicates the succession of bacteria populations in the bioleaching process.After the bioleaching for 21 days,the rate of bioleaching in low-grade nickel sulfide ore has reached to 70%.Realizing that the bacteria population structure is closely related to the rate of bioleaching could help to optimize the bacteria population structure and improve the rate of bioleaching.