Te-tsun Yu was taught by Hu Xiansu.
Te-tsun Yu was a co-founder of the Kunming Institute of Botany. He worked as editor of the Flora Reipublicae Popularis Sinicae and director of the Institute of Botany at the Chinese Academy of Sciences.
In 1979 Te-tsun Yu toured the United States as part of a delegation from the Botanical Society of the People's Republic of China in reciprocal arrangements with the Botanical Society of America. This collaboration led to the Flora of China Project which started shortly after Yu's death and was first published in 1994.
Te-tsun Yu was a prolific collector of plant specimens in Yunnan, making expeditions into the largely unexplored mountains in the north west of the province. Thousands of specimens he collected were exported to Arnold Arboretum in Boston, Massachusetts and Royal Botanic Garden Edinburgh who funded the expeditions in 1937.