Abstract: In order to construct the metagenomic library of microorganisms from salt lake soils in Yuncheng， the microbial metagenomic DNA extraction method was explored. Six of plant genomic DNA extraction methods were modified to extract the microbial metagenomic DNA. The yield and quality of the metagenomic DNA was detected by ultraviolet spectrophotometry， gel electrophoresis， restriction endonuclease analysis and PCR amplification， and the results showed that the modified method 3 was suitable for extracting the microbial metagenomic DNA from salt lake soils in Yuncheng. For the microbial metagenomic DNA extracted by the modified method 3， the value of OD260/280 was 1.883， the concentration and yield was 18.1 ng·μL-1 and 72.4 ng·g-1 respectively， and the length was about 23 kb with a clear stripe on the agarose gel. Moreover， the metagenomic DNA was completely digested with EcoRⅠand also could be used for PCR amplification.

Key words: salt lake soil, microorganisms, metagenome, metagenomic DNA, extraction method