 In 1932, he was transferred to Yunnan province, where he worked as a botanist in the province's temperate climate.In 1938, he set up the Yunnan Botany Research Institute () in Heilongtan, and acted as the institute's Vice President.In 1950, Cai Xitao was given charge of the Kunming Institute of Botany, Chinese Academy of Sciences (CAS), and in 1959 the Xishuangbanna Tropical Botanical Garden) was established under his control.