Mark Julius Ginsbourg was born in 1909 in Barim, Manchuria, in the Qing Empire (today Balin [巴林鎮], Yakeshi in Inner Mongolia, China) to Russian-Jewish parents who had migrated from the Russian Empire. He went to school in Vladivostok in the Soviet Union and then in Shanghai, China. He was accepted to Pomona College in Claremont, California, in the United States where he majored in political science. Following his graduation from Pomona, he entered the School of Journalism at Columbia University, graduating in 1934.
Ginsbourg got into his career in the 1930s as a stringer (journalism) for Washington Post in the Shanghai. He returned to the U.S. shortly after World War II broke out in Europe, changing his name to Gayn to prevent Japanese reprisals against his brother Sam, who remained in Japanese-occupied Shanghai. Gayn also went on to write for Collier's and was arrested in the FBI raid on the offices of the Institute for Pacific Relations' Amerasia office in June 1945. At the time of his arrest, he was reporting not only for Colliers but also the Chicago Sun as well as TIME Magazine.
However, the charges were dropped shortly thereafter—the New York Times described him as "quickly vindicated in the courts." The State Department refused to admit his Hungarian-born wife Suzanne Lengvary to the United States, on the grounds of her alleged Communist sympathies, so he moved to Canada and continued his work as a foreign affairs correspondent.
He filed reports on North Korean dictator Kim Il Sung's repression and, as one of the first Western journalists admitted into China in the mid-1960s, he managed to criticize the country's Maoist regimentation.
During his life, Mark Gayn wrote four books: The Fight for the Pacific published in 1942, Journey From the East: An Autobiography published in 1944, Japan Diary published in 1948 and republished in 1989 and New Japan Diary which was published after his death in December 1981.
- There is a typescript guide to the contents: Collection Guide to the Mark Gayn Papers (MS Col. 215), prepared by Graham S. Bradshaw. An exhibition and catalogue with material from this collection were created in 2016, Reading Revolution: Art and Literacy during China's Cultural Revolution, by Jennifer Purtle and Elizabeth Rodolfo, with contribution by Stephen Qiao
- Graham S. Bradshaw. "Guide to the Mark Gayn Papers." Thomas Fisher Rare Book Library, University of Toronto, 1988. Retrieved 20 July 2017.
- Mark Gayn Dead at 72, Jewish Telegraphic Agency, Dec. 28, 1981
- MARK J. GAYN, 72, JOURNALIST; SPECIALIST ON FOREIGN AFFAIRS, The New York Times, Dec. 24, 1981
- Klehr, Harvey; Radosh, Ronald (1996). The Amerasia Spy Case. University of North Carolina Press. pp. 50-1 (bio). Retrieved 19 March 2020.