The American Science journal, on the occasion of its 125 publication anniversary, in 2016, released 125 of the most challenging scientific issues (Kennedy et al., 2005) to the world. According to the basics, breadth and the influence, 25 of the issues which considered to be the most important were screened, including “How many people can the Earth carry?” (Stokstad, 2005; Dailyg et al., 1992; Cohen, 1995) and “How high will the greenhouse effect make the earth temperature?” These two scientific problems are based on resources and the environment: the population limit that the earth can carry is related with the land and surface water resources and ecological environment carrying capacity; the root of the greenhouse effect is the increase of CO 2 in the atmosphere, and the soil is the largest carbon bank in the terrestrial ecosystem, the impact of soil resources on the greenhouse effect can not be ignored. Traditional soil resources are only problems related to agriculture or human food and clothing and can no longer fully reflect the overall function and value of the soil. The soil not only provides food and fibre for human beings, but has social, ecological, economic, cultural and spiritual dimensions (Robinson et al., 2012), It also plays an irreplaceable role in ensuring environmental safety and energy security, documenting the evolutionary history of the earth and humanity, and protecting biodiversity, and the soil is at the heart of safeguarding the structure and function of the Earth’s ecosystems. 1 Overview of black soil resources There are only four black soils in the world, all developed in the mid-latitudes, in Northeast China, North America, Ukraine to Southern Russia and South America’s Pampas, with a total area of about 916 million hectares, accounting for about 7% of the world's frozen soil. The three black soils of the northern hemisphere are mainly distributed in the middle and low latitudes at the core of the North 46° belt (Fig. 1); The black soil region of North America straddles southern Canada, the central plains of the United States and northern Mexico, About 290 million hectares; the black soil region of Eurasia began in the sub -humid grasslands of south-central Europe, extending intermittently to Russia and northeastern China, about 450 million hectares; and the black soil region of South America is mainly located in Argentina and Uruguay, about 102 million hectares. 2 Proposal of the concept of black soil critical zone The earth system is an organic whole composed of the atmosphere, hydrosphere, continental circle (crust, mantle, core), and a biosphere (including humans). Earth System Science is the emergence of the fundamental living environment crisis facing mankind-the severe challenge of global change, the study of the composition of the earth system subsystem between the interconnection, the mechanism of interaction, the law of changes in the earth system and the mechanism to control these changes, so as to establish a scientific basis for global environmental change prediction, and for the scientific management of the earth system to provide a basis. According to the content of earth system scientific research, a scientific concept is needed to express the research object in earth system science. Since 2001, the National Research Council of the United States, the National Science Foundation of the United States, the Pennsylvania State University Susan Brantley, Lin and others have made different representations of the areas covered by the Earth's critical zone (Brantley et al., 2005; Lin et al., 2005; Lin, 2010), pointing out that the earth’s critical zone is a complex, interdependent, network “focus” areas composed of geological, geochemical, biological, hydrological, geomorphological and atmospheric processes, with spatial boundaries ranging from the vegetation canopy to the bottom of the groundwater aquifer, containing the near-surface biosphere, the atmosphere, the entire soil circle, as well as the hydrosphere and lithosphere surface/ near surface parts. Matson first summed up the connotations of soil circles in 1938 and pointed out that soil is the product of the Background and Research Prospect of Geo-ecological Survey and Monitor in the Critical Zone of Black Soil LI Zhizhong 1 , WANG Daming 2 , DAI Huimin 1, * , WANG Xisheng 3 , LIANG Shuai 1 , XU Jiang 1 , YANG Jiajia 1 , WANG Lei 4 , CHEN Shengbo 5 , Alecos DEMETRIADES 6 , Veronika KOPAČKOVÁ 7 , Igor SAVIN 8 , Douglas A. HOWARD 9 , Timothy FILLEY 10 and GENG Xiaoyuan 11 1 Shenyang Geological Survey of China Geological Survey, Shenyang 110030,Liaoning,China 2 China Geological Survey, Beijing 100000, China 3 Institute of Geomechanics, Chinese Academy of Geological Sciences, Beijing 1000000, China 4 British Geological Survey, Ctr Environm Sci, NottinghamNG12 5GG, England 5 Jilin University, Changchun 130026, Jilin, China 6 Institute of Geology and Mineral Exploration, Olympic Village, 13677 Acharnae, Athens, Greece 7 Czech Geological Survey, Remote Sensing Department, Prague,118 21, Czech Republic 8 Russian Academy of Sciences Kirensky Institute of Physics,Krasnoyarsk,660036, Russia 9 Department of Geology, Arizona State University, Tempe, Arizona,85287-1404,USA 10 Purdue Univ, Dept Earth Atmospher & Planetary Sci, 550 Stadium Mall Dr, W Lafayette, IN 47907,USA 11 Kentville Research and Development Centre, Agriculture and Agri-Food Canada, Kentville, NS B4N 1J5, Canada Citation: Li et al., 2019. Background and Research Prospect of Geo-Ecological Survey and Monitor in the Critical Zone of Black Soil. Acta Geologica Sinica (English Edition), 93(supp. 1): 126-129. * Corresponding author. E-mail: daihuimin78@126.com Acta Geologica Sinica (English Edition), 2019, 93(supp.1): 126–129 © 2019 Geological Society of China http://www.geojournals.cn/dzxbcn/ch/index.aspx https://onlinelibrary.wiley.com/journal/17556724