| Tetraena Mongolica, which is only found to be very xerophytic and gregarious on sandish grassland of West Erdos in Inner Mongolia, belongs to an endangered relic plant species of Zygophyllaceae. Its existence plays an important role both in the flora and systematic evolution and in the protection of ecological environment. In recent years, owing to various factors, its distribution has been becoming dissected and narrower, so this plant species has fallen into the categories of the second-classed protected species by the State.So far, researches on Tetraena Mongolica have been made in different levels, such as climate and physical geography, biological characteristic, adaptability in physiological-ecolgy, pollination insect, fragmentation habitats, and community, group, individual, cell, genetic structure, etc. There is lack of comprehensive analysis on the specific environmental and geographic condition(colliery and mineral resources underground) in study area.Aim at probing into the particularity of microbial flora in the rhizosphere of Tetraena Mongolica and the bulk soil in study area, and the inherence between colliery and soil element content ,species and activity of soil microorganisms, this paper made study of Tetraena Mongolica on the soil physical chemistry, construction of soil microbial flora, community structure and diversity, dynamic changes in amount,ect, so that scientific theoretical foundation could be obtained to study the suitability for. Tetraena Mongolica in natural condition of distributive area and exsitu conservation. The results are as follows:1. There is a magnificent difference in organic matter and pH between the area with colliery and the area without. The content of organic matter in the area with colliery(A) is higer than the area without(B), but the pH is contrary. There is a magnificent difference in total and available nutritional elements between the area with colliery(A) and the area without(B). The total N P K in the area with colliery(A) is higer than the area without(B): There is difference in total and available micro-elements between the area with Colliery and the area without. The total content of Cu, Fe, Mn, Zn, B in soil is higer in the area with colliery(A) than in the area without(B). The available content of six kinds of micro-element such as Cu, Fe, Mn, Zn, B, Mo indicates the same results as above.2. The sequence of microbes in the construction and ratio of microbial community in microbial flora of study area is as follows: Bacteria＞Actinomycete＞Anaerobic-Bacteria＞Fungi. Bacteria and Actinomycete are in the dominant situation in microbial flora. The large ratio of Actnomycete in microbial flora embodys the bad condition of barren soil in deseh. The activity of microorganisms in rhizosphere of Tetraena mongolica embodys distinct regulative changes, that is low-high-low corresponding to growth peroid, blooming period, fruitation period in the whole growing season. This indicates that microorganisms are active in rhizosphere of Tetraena mongolica in the blooming period. However, R/S of Tetraena mongolica is distinct and regulative in the whole growing season, that is high-low-high corresponding to growth peroid, blooming period, fruitation period. There is a magnificant difference in amount of microorganisms and R/S between the area with colliery(A) and the one without(B). The amount of microorganisms is higher in the area with colliery(A) than the one without(B), but the result of R/S is contrary. (R/S)_B＞(R/S)_A.3. The amount of Bacteria, Fungi, Anaerobic-Bacteria is correlative with the amount of micro-element, such as Fe, Mn, Cu, Zn, B, Mo, which is necessary to development and growth of plant. The correlation is significant between the amount of Bacteria and total Cu (97.1%), available Cu (91.3) and Mn(87.7%). The amount of Anaerobic-Bacteria is significantly correlative with total Fe and total Mn. So, Bacteria in soil maybe play an important role in the decomposition Fe, Cu, Mn and the nutritious matter available to plant.4. A method of DNA extration from soil samples was obtained based on prevenient methods and mass of experiment. It is timesaving and low request for equipment. An comparation was made between the new method and the mature method in existence. The result is that the new method is more suitable for the soil microorganisms DNA extraction in study area. The yield and purity of DNA products extracted from soil is better. The DNA products could be used for 16S rDNAPCR directly.5. PCR-DGGE was used to analysis the bacteria diversity in the soil of study area. There is a magnificant difference of the genetic diversity of Bacteria in the distributive area of Tetraena Mongolica, between the area with colliery and the one without colliery. Bacteria community came from the same type of area has the similar origin in phylogenetic. And that. came from different type of area(with colliery and. without) has magnificant difference. Dominant bacteria and specific bacteria were found in study area. And they had magnificant correlations with the geographic and ecological environment.6. Changes of soil microbial biomass(MB) is found between years. Microbial biomass embodys low-high-low corresponding to growth peroid, blooming period, fruitation period in the whole growing season, It indicates that microorganisms is active in blooming with large C content in soil.7. The activity of soil enzyme is not significant between the area with colliery and the one without. The activity of soil enzyme is high in July than in May and September. Activity of urease is significant correlative with MB, invertase, peroxidase. So urease, invertase and peroxidase had associative effection.8. In two years, some has been made in the study of the soil microorganisms of the endangered relicit plant Tetraena mongolica Maxim. in distributive area. But in thie specific region where Tetraena Mongolica distributed, the intrinsic relation between colliery and soil environment is the result of long-term interaction. So further and extra research is needed to know the detailed relationship.
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