Mao Zedong in his later years had cognitive deviations on cultural issues,which led to the launch of the "Great Cultural Revolution".These deviations are mainly embodied in three aspects,namely confusing two types of contradictions of different natures in cultural field,widely using exaggerated methods in cultural debates and obviously deviating on general understanding of cultural front.It is of greatly methodological significance for an overall grasp of Mao Zedong Thought and for the reinforce of socialist cultural construction to profoundly hold the interrelationship between Mao Zedong’s cognitive deviations on cultural issues in his later years and the launch of the "Great Cultural Revolution".