Culturable microorganisms provide very limited information on soil microbial diversity, because only 0.1%-10% of soil microorganisms can be cultured under conventional laboratory conditions. A novel culture-independent approach, i.e., metagenomic methodology, has been developed as an effective tool for the discovery of new natural products and microbial functions. Soil metagenomic methods, comprising isolation of soil DNA and construction and screening of clone libraries, enable to peep at more complete scenario of soil microbial communities, and thus, to better understand their interactions. This methodology is of great potential for use in the studies of soil microbial communities and their functional genes, and in the discovery of new biocatalysts for industry and pharmacy. This review summarized some advances of soil metagenomic study.