Professor Tianren YU was born in 1920 in Shandong Province and passed away in 2004 in Nanjing,China.He graduated from the Department of Agricultural Chemistry,Northwest Agricultural College,China in 1945 and worked as as-sistant professor from 1950 to 1953 in Institute of geology,Chinese Academy of Sciences(CAS).Since 1953,he worked as assistant professor,associate professor,and professor in Institute of Soil Science,CAS and was elected as an academician of CAS in 1995.