Abstract: People usually pay close attention to the converge trend of Yi and Lao under the influence of metaphysics during the Wei and the Jin Dynasties and regard it as the new fashion of those ages. In fact，both Zhouyi and Laozi，classical books honored by Confucianism and Taoism respectively，but they are also associated with each other in many aspects，which makes up the ideological foundation of the integration trend of Yi and Lao. Such trend was carried on continually by scholars，such as Sima Jizhu in the early Western Han Dynasty，Yan Zun and Yang Xiong between the end of the Western Han Dynasty and the beginning of the Eastern Han Dynasty，and Ma Rong，Zheng Xuan and Yu Fan，etc. during the end of Eastern Han Dynasty，who were regarded as the predecessors of metaphysics by complementing Yi with Lao，or vise versa，during the Wei and the Jin Dynasties.

Key words: Zhouyi, Laozi, integration, metaphysics during the Wei and the Jin Dynasties