Cover Story：Eco-geological map of the earth critical zone (part of Changning Sheet in Hebei Province). Under the guidance of the earth systems science and local ecological environment, 1:50000 earth critical zone survey and mapping were carried out in the lower reaches of Luanhe River in the Changning Sheet (J50E003020) of eastern Hebei Province with the purpose of better understanding the interaction and binding mode between the atmosphere, plant, soil and groundwater layers. The eco-geological map of Changning Sheet can provide a new idea for the study of earth critical zone in large area and also provide geological basis for the solution of the problem concerning the over standard lead content in corn in the Luanhe River catchment. The research result was achieved by the research group led by SHI Jian-sheng and MA Rong, Institute of Hydrogeology and Environment Geology of CAGS. For details see pp. 767-780 of this issue. (Photo by SHI Jian-sheng)