Abstract:

Earth Critical Zone was formally proposed by the American Research Council ( NRC) in 2001．Then United States，South Africa，China and other countries，and relevant international organizations，such as the European Union，organized and deployed research projects，as well as developed the related research plan，established observation web site for a long time，to strengthen and promote Earth Critical Zone research．In this paper，based on SCIE database，the relevant papers，research reviews，conference papers and other relevant documents from 2001 to 2015 were retrieved．Based on the Earth Critical Zone studies，the results show that: 1) the overall research papers of Earth Critical Zone show the fluctuation growth trend; 2) America and its research institutions have absolute advantage in Earth Critical Zone research，but Chinese institutions still need to further improve the research strength; 3) From the hot spot change，research topics，including critical zone，hydrology，soil，etc has become the most concerned for the major countries and institutions; 4) Interdisciplinary research is key important organization mode to Earth Critical Zone research．Finally，the four future key research directions of Earth Critical Zone in China are put forward．

Key words: bibliometrics, Earth Critical Zone, earth science, progress and trends, analysis