Abstract: The leap theory  in Marx’s later years is not  a multi-lineal theory,instead,it refers to the dialectical unity of the outlook of world history and the outlook of historical materialism.The later is included in the former and the former is based on the later.The sequential thought of social development should be understood from the perspectives of time spirit,human history,and world history.Marx’s leap theory can also be used to explain the historical inevitability of the success of Chinese revolution.

Key words: leap theory, outlook of historical materialism, outlook of world history, Chinese revolution