五四運動爆發時，世間尚無中共，自無中共黨員可言。日後的中共人物裡，則不乏曾經涉足五四運動者，尤以「南陳北李」陳獨秀與李大釗為最著，而為大陸史書所樂道，彼等在五四運動前後的言行真貌，亟待還原與解析。後來崛起的毛澤東與周恩來，在五四運動時的思維與角色，亦有檢討以明真相的必要。五四運動前夕，陳獨秀鼓吹民主與科學，加上革新政治的工具新文學，三者構成新青年以至新文化運動的主要內容。陳獨秀念茲在茲，拳拳服膺，馬克思主義此時在他的思維中，近乎一片空白。李大釗被視為中國傳播馬克思主義的第一人。其實，他雖然批判繼承了馬克思的經濟學說，但始終強調互助論，對馬克思的社會主義倫理觀要待完成階級鬥爭後，人類真正理想王國才會來臨的理論，深表懷疑，認為應予修正。毛澤東對五四運動的政治參與，扮演了一種響應者的角色，其聲音與力量多集中在湖南一省，影響的就全中國而言自屬有限，內容也多與馬克思主義無關。此時他對無政府主義的推崇，超過了馬克思主義。周恩來本著救國的純潔動機，參加了五四運動，也演出一個地區性的角色。沒有任何證據顯示，他把馬克思主義摻雜在這項愛國運動裡。此時他的理念，完全反映了五四運動的內容 When the May Fourth Movement took place, the Chinese Communist Party (CCP) had not yet come into existence. However, some active participants in the movement later joined the CCP. The most important among them were Chen Duxiu and Li Dazhao. Mao Zedong and Zhou Enlai also played key roles in the movement.On the eve of the May Fourth Movement, Chen Duxiu strongly advocated democracy, science, and a new instrument of political reform－new arts. These were the main content of Xin Qingnian (New Youth) and the New Culture Movement. At that time, his writings showed almost no trace of Marxism.Li Dazhao is regarded as the first propagator of Marxism in China. However, although accepting, with some reservations, Marx's economic theories, Li consistently emphasized mutual assistance and doubted Marx's assertion that utopia could emerge only through class struggle. He thought that this socialist ethics needed to be revised.Mao Zedong played the role of a supporter in the May Fourth Movement. As his activities were concentrated in Hunan Province, he had limited influence on China as a whole.