Abstract: Han Yu was not only a famous litterati in Middle-Tang,but also a key figure in the sense of changing was one of the leaders in the literary world of Yuan-He time. He made innovations and changes in his works,such as their content, function, skill, style, etc. Moreover,he extended the domain in which poetry was applied;he led the poetry style of Middle-Tang to customs and particularity;he made good use of the prose in writing his poems and the vice versa. All of those formed his key status in the changing process of the poetry in Middle-Tang. Besides, the wide spreading of his poems and prose in Song dynasty and the great influence he had on Song writers strengthened his connecting function in the changing process from Tang-Style to Song-Style.