Abstract: There are increased interests on investigating the mechanisms of microbial mineralization.Comprehensively using different kinds of analytical methods, such as electron microscopy, atomic force microscopy and X-ray absorption fine structure, the present paper studies the structural transformation information during the process when Ochrobactrum sp. interacts with heavy metal chromium. It is proposed that the investigation of structural information was in nano scale. Together with related molecular biological results, the investigation is helpful in understanding the mechanisms of microbial mineralization.