A series of recent progress on the study of the carbon sink of rock weathering have been made with the increase of CO2 concentration in the world. A lot of research shows that karst process plays an enormous role in carbon sinks. Furthermore, metabolic activity of microbes plays a positive role in the carbon sinks of karst. Microalgae as the oldest and the most important primary productivity, interaction effect between the growth of microalgae and the rock weathering and the regulatory mechanism are discussed in this thesis. The study results are extended to geochemical environment background. This work has profound implications to further discuss the geological significance of microbe’s corrosion and effects on the world's carbon cycle.It can provide scientific basis in search of “missing carbon sink” to study the silicate rock corrosion of microalgae (using olivinite as an example) and the discussion on the silicate rock corrosion effect of microalgae and the changes of microalgae carbon sink during the process of silicate rock corrosion and weathering. Finally, a technology of biology carbon sinks addition. Acetazolamide (AZ, for short) is one of inhibitors of CAex and the CAex activity can be specifically inhibited by AZ. The 4, 4-diisothiocyanatostilbene-2,2-disulfonate (DIDS, for short) is the inhibitor of anion channel and the activity of anion channel can be specifically inhibited by DIDS. The metabolic pathways of inorganic carbon are affected by the two inhibitors. Thus，olivinite biological corrosion effect of microalgae and its carbon sink are studied by adding DIDS and AZ in the thesis. Chlamydomonas and chlorella are chosen as experimental materials in this thesis. Mg-olivinite corrosion weathering has been studied by controlling different conditions, for example, the two kinds of microalgae in nutrient-rich and nutrient-poor environment, adding AZ, adding DIDS and different pH values. Meanwhile, the calculation method of inorganic carbon utilization share was used to probe into the response mechanism of carbon sink effect of microalgae in above different conditions. Following principal achievements have been obtained in this thesis:(1) Calculation method of stable carbon isotope fractionation value has been established during the process of CO2 assimilation of microalgae in this thesis. Additionally, the calculation method was used to study the inorganic carbon utilization share. The study found that the share of HCO3- way is usually very high in the three kinds of karst lake microalgae named Chlamydomonas reinhardtii(C.R), Chlorella pyrenoidosa(C.P) and compound algae collected from surface water of Hongfeng Lake. The result shows that the HCO3- way is mainly the inorganic carbon utilization share of microalgae in the karst lake. It is the result of survive strategy choices of microalgae in a long-term lack of CO2 aquatic environment.(2) Corrosion weathering of olivinite promotes biological carbon sink function of microalgae; Microalgae all increase amount of dissolution and weathering, whether external environment lack of magnesium. Microalgae may use ions produced from olivinite corrosion to provide the nutriment for its own life and promote its growth. In this way, biological carbon sinks are added. Chlamydomonas reinhardtii can still grow normally and keep higher biological carbon sink function in nutrient-poor external environment. Two kinds of microalgae can be a great boost for dissolution and weathering of olivinite, whether external environment lack of magnesium. So olivinite dissolution function of microalgae may not change dramatically with the change of external environment. According to previous estimate model of global carbon sink, rock chlorella microbes of all river watersheds in Karst weathering areas are ignored. It leads to carbon sink effect of rock weathering is underestimated. Thus, this conclusion provides a new direction to find the “missing carbon sink”. (3) Biological carbon sink of may be added when microalgae is restrained; Meanwhile, discover CAex activity is the important impact factor of corrosion weathering of olivinite and promote the corrosion weathering function. The HCO3- way produced from the CAex catalysis may be restrained when microalgae is restrained. So the growth of microalgae reduces and the demand for required carbon source decrease, thus reducing the low carbon source stress and biomass increase and biological carbon sink of microalgae increase. CAex activity may be especially restrained by AZ. Biological corrosion function of microalgae may be restrained when the HCO3- way produced from the CAex catalysis is restrained. The results show that CAex of microalgae plays a great role in dissolution and weathering of olivinite.(4) DIDS can promote the biomass growth of microalgae and add the biological carbon sink; Anion channel is the important positive impact factor for the olivinite dissolution and weathering of microalgae. A clear anion channel plays a promoting role in olivinite dissolution and weathering. Biological corrosion function of microalgae is restrained by the DIDS.(5) The share variation values of HCO3- utilization way among the two kinds of microalgae is different when anion channel is restrained by DIDS. The reason of phenomenon relates closely with the CAex activity of this two kinds of microalgae. Chlorella with low activity of CAex shows higher share values of HCO3- utilization way when it is restrained by DIDS. It shows that HCO3- utilization way of CAex catalysis of microalgae start to activate at the moment. However, the share values of HCO3- utilization way decrease obviously when chlamydomonas reinhardtii is restrained by DIDS. The result shows that the CAex activity of chlamydomonas reinhardtii is high and its catalytic HCO3- utilization way has been express fully.(6) In the case of external pH change, dissolution and weathering of olivinite may be restrained while adding microalgae. This result is not inconsistent with the conclusion that the microalgae growth can promote to dissolution and weathering of olivinite. The main reason is that this phenomenon is related to microalgae biomass. The microalgae biomass during experimental treatment pH reduces compared with initial value, which should lead to reductions in biological corrosion of microalgae for olivinite. Microalgae may restrain olivinite corrosion to accommodate life action with changed pH during the collapse of the microalgae. The growth of microalgae is influenced by many factors in field akes. If impact of the growth of microalgae is ignored in estimating corrosion and weathering of silicate rocks, weathering carbon sink would be underestimated or over estimated.(7) The variation share of the inorganic carbon utilization way is mainly related with pH change. The share of HCO3- utilization way of chlamydomonas reinhardtii gradually decreases with the increase in pH value. However, the share of HCO3- utilization way of chlorella first rise and then drop. This rule is not changed by adding olivinite and shows that the share of the inorganic carbon utilization way is mainly related with pH value.