On September 1847 Moses White and Jane, along with Judson Dwight Collins, arrived in Foochow, beginning their missionary work there. Jane, however, fell sick shortly afterwards and finally died of consumption on May 25, 1848, at the age of 26. In 1851, White was married a second time to Mary Seely, who came from Onondaga, New York and also went to Foochow as a missionary.
During his seven years in Foochow, Moses White conducted a school for the secular and religious instruction of the Foochow people, and after mastering the local Fuzhou dialect, he translated the Gospel of Matthew, which was the first Christian document ever published in that vernacular. At the same time, White also served as a doctor, studying and treating the toxic effects of opium.