Methods for describing and characterizing soil microbial diversity, including population diversity, community diversity, gene diversity and function diversity, were discussed in this paper. A series of laboratory methods for measuring soil microbial diversity were reviewed and some new technologies, such as Biolog micro-plates, PFLA analysis and molecular biological techniques (such as PCR, DGGE, RAPD, RFLP, AFLP, SSR) were introduced as well. Meanwhile it was suggested that if possible, it is advisable to combine some of the methods in the test so as to get more accurate and comprehensive information and a better understanding of soil microbial biodiversity.