Magnolia Officinalis Cortex has been used as a traditional Chinese herb for thousands of years in China. According to Chinese Pharmacopoeia,the processing of Magnolia Officinalis Cortex needs " sweating" or " Fahan",which was a special drying process and considered to be an important symbol for high quality and genuine medicinal materials. In this unique processing mode,Magnolia Officinalis Cortex's microbial community structure may be changed,but little is known about microbial diversity during the " sweating". In this study,to analyze the change and its change rules of microbial community of Magnolia Officinalis Cortex in the whole process of " sweating",and find out the microbial community that affects the quality of Magnolia Officinalis Cortex in the process of its " sweating",and provide a basis for further research on the microbial transformation of Magnolia Officinalis Cortex,MiSeq highthroughput sequencing was used to evaluate the microbial diversity of natural " sweating" of Magnolia Officinalis Cortex. In this research,334 genera fungi and 674 genera bacteria were identified. The dominant species weren' t obvious during the early stage of " sweating". Candida was the dominant fungal species( 45. 01%-71. 93%) during the medium " sweating" stage. Aspergillus is the dominant fungal species( 45. 83%-95. 51%) during the late stage of " sweating". Moreover,Enterobacter and Klebsiella were the primary bacterial genus( ≥56. 05%) during the middle and late stages of " sweating". In addition,the predominant bacteria in the process of " sweating" included Bacillus,Deinococcus,Sphingomonas,Hymenobacter and Jatrophihabitans. In conclusion,the microbial diversities and the main dominant fungi and bacteria in the process of " sweating" of Magnolia Officinalis Cortex were initially determined. It was also found that the metabolism of Aspergillus and Candida may be related to the character formation,which were sweet odor and brown inner surface after " sweating". The results provide a theoretical basis for the study of the influence of different microorganisms on the excellent traits formation of " sweating" Magnolia Officinalis Cortex.