In 1940, he traveled to the United States, and earned a Ph.D. in Biology from Harvard University in 1942.
From 1943 to 1946 Li studied under Francis W. Pennell and Jacob R. Schramm at the Academy of Natural Sciences of Philadelphia.
In 1958 Li joined the faculty at the University of Pennsylvania, where he remained until retiring in 1979.
[2] Some notable books are: Li was chair of the editorial committee and a contributor to the (1975-1979) Flora of Taiwan, and the first translator of the c. 304 Nanfang Caomu Zhuang "Plants of the Southern Regions" (1979).
Li was elected a member of the Academia Sinica, Taiwan in 1964, and was a visiting Professor of Biology at the Chinese University of Hong Kong from 1964 to 1965.