The Former Yan was a state of Xianbei ethnicity and founded by Murong family during Wei, Jin, Southern and Northern Dynasties. Tuoba was a clan of the Xianbei people and they established the state of Dai and Northern Wei Dynasty. The Former Yan and Tuoba had already established diplomatic relations quite a long time ago. In the Book of Wei had recorded several contacts between each other, including paying tribute, connecting by marriage, and making contact through messengers. The main purpose of this paper tried to investigate the interaction and marriage relations between the Former Yan and Tuoba. Besides, some overstatements and errors in the historical documents of that period were also clarified by the author.