The paper reviews André Paul Guillaume Gide’s trip to the Soviet Union in 1936 and Edgar Snow’s trips to China in 1960, 1969 and 1971. It explores the social background when two western authors visited   the socialist countries, and discusses their reports and achievements.In order  to disclose what      they were thinking during their visits, this paper tries to answer the following questions:   Why these   two western authors got different understandings of the socialist countries? What are the underlying reasons behind their different reactions-different personalities or other historical reasons? What is the reason that led to Snow’s mistakes in interviews during the last 30 years if  he did make some.