In 1937 Chern left Paris to become professor of mathematics at Tsing Hua University. However the Chinese-Japanese war began while he was on the journey and the university moved twice to avoid the war.
Sa 1937 Chern kaliwa Paris upang maging propesor ng matematika at Tsing Hua University. Subalit ang mga Chinese-Japanese war nagsimula habang siya ay sa paglalakbay at ang unibersidad inilipat ng dalawang beses upang maiwasan ang digmaan.