1949年以后郭沫若在学术上多次变化的种种表现,是有时代原因的。他从大革命时代开始便投身革命,将学术与文艺服务于现实斗争需要。他所扮演的角色是战斗火线上的匕首、投枪、革命军中的马前卒。本文主要探讨郭沫若自二、三十年代开始,关于中国社会形态发展阶段的论点,以及对某些历史人物评价的变化及其原因。 There are times reasons for the various manifestations of Guo Moruo’s academic changes after 1949. From the beginning of the Great Revolution, he devoted himself to the revolution and served academic and literary work in the real struggle. He plays the role of a dagger on the battle line, a gun, and a pawn in the Revolutionary Army. This paper mainly discusses the arguments of Guo Moruo since the 1920s and 1930s, the stages of the development of Chinese social form, the changes of the evaluation of certain historical figures, and the reasons for the changes.