abstract: Deoxyribonucleic acid is a ubiquitous compound of the soil environment, constituting genetic information indispensable for soil microorganisms biodiversity determination. Year of 2010 has been announced by UN as International Year of Biodiversity, in order to paying an attention on one large section of global biodiversity for too long ignored: soil biodiversity. However, knowledge about soil microbial biodiversity is still limited, most of all by the fact that only 1% of soil microorganisms population could be isolated by use of traditional laboratory methods. Soil bacteria consist the huge quantity of genetic information, which constantly remained inaccessible for traditional microbiological tests. That is why, progressive techniques of molecular biology are more and more exploited at investigations of bacterial population in the soil environment. An isolation and DNA analysis complete with more and more precise molecular techniques (i.e. PCR with its variety, CLPP, PLFA, DGGE, FISH) are nowadays the basic and how important explorative tools, approximating us to closer recognition of life environment and biodiversity of soil organisms. In the current work the most popular molecular methods useful in the soil DNA determination and leading to microbial identification are presented. Choice of the proper molecular method should be anyhow adjusted to the problem, which may be solved: detection, identification, differentiation, taxonomic investigations. Technical aspects are also of great importance: analysis difficulties, experience, research background, costs of method applied. Description of both advantages as disadvantages of the most popular analytical methods should be helpful for researchers standing before decision about selection of the proper technique for soil DNA analysis.