ABSTRACT
<p><b>OBJECTIVE</b>To study the characteristics of soil microbial variation during Salvia miltiorrhiza crop rotation.</p><p><b>METHOD</b>the conventional cultivating microbial method was used to study the microbial number and communities structure and soil microbial biomass phosphorus (SMBP) was determined by chloroform vapor extraction method. The data was then analyzed by SPSS software.</p><p><b>RESULT</b>With the increase of the crop rotation years, the numbers of bacteria and actinomycetes in soil also, but the fungi and SMBP decreased.</p><p><b>CONCLUSION</b>Microbial mechanism of crop rotation of the planting S. miltiorrhiza is the regulation of microbial number and bacteria physiological communities, the process rebuilds the soil ecological system balance. Microbial communities in soil need at lest 2 years to get to restore, after planting S. miltiorrhiza, which consisting with traditional planting experience.</p>