Abstract:Microbial community and biodiversity of different samples from acidic heap leaching and bio-heap leaching process were analyzed by 16SrRNA gene clone library-sequencing methods and principle component analysis to compare differences among all samples and investigate key factors effecting community’s components. The results indicate that microbial abundance and richness are higher in acidic heap leaching system than those of in bio-heap leaching, and predominant species of bacteria are At. ferrooxidans, L. ferriphilum and At. thiooxidans in all samples, which are the main groups in bioleaching. PH value and total fluoride iron concentration are the key factors to impact microbial abundance and richness in the uranium leaching plant. Feeding culture is the key factor to keep microbial communities stable and active in bio-heap leaching processing.