The Huaihe river has inspired poets for many years, especially in the Northern Song Dynasty (AD 960-1127), the Southern Song Dynasty (AD1127-1279), and the Yuan Dynasty (AD 1271-1368). The poetry of Huaihe river was, however, changed dramatically between the Northern and Southern Song Dynasties. In this essay, I discuss the reasons why this happened from the social and historical points of view. My opinion is that the poetry of the Huaihe river in the Southern Song Dynasty is made from the patriotic sentiment of poets.The early poetry of the Huaihe river had been established by the middle of the Northern Song Dynasty. It was often described as a favorite object of scenery that liberates the spirit of poets from the bustle and wiles of the city. However, the Northern Song Dynasty was invaded by the Jin Dynasty in 1127 (the conflict of Jingkang) and forced to lose its northern territory beyond the Huaihe river. Since then and until the unification of the Yuan Dynasty, the Huaihe river had been just a military border that not only protected against hostile neighbors but also sorrowfully separated their own country into halves. Thus, the poetry of the Huaihe river in the Southern Song Dynasty became a symbolic object of scenery that continually forced poets to feel tension and humiliation.I would like to point out that the poetry of the Huaihe river in the Southern Song Dynasty was also affected by the professional mentality of so-called poets. In the Northern Song Dynasty, many bureaucrats traveling north or south across the Huaihe river on duty must have played on a boat in this great river and enjoyed the spectacular scenery of surrounding mountains. Thus, the poetry of Huaihe river made by such beurocratic poets must be glorious, spectacular, gorgeous and relieving. In the South Song Dynasty, however, reflecting its military tension, only professional soldiers or military officers could visit there as local governors, none of whom was recognized as a poet by later generations. For these people, the Huaihe river was just a military object but not a favorite object of scenery. In such circumstances, only civil officers who sent off or met an envoi for or from Jin in the border could cross the river and approach the north shore.In Chapter 3, I introduce some examples of bureaucratic poets who came to visit Jin and summarize how they feel the poetry of the Huaihe river. I noticed that these poets are free from the tension and always feel relaxed, but have a different sense of freedom from that felt by poets in the Northern Song period.In Chapter 4, I introduce Yang Wanli, an envoi attendant who created the largest number of poems on the Huaihe river, and discuss why he did not compose poems on the devotion to his country or patriotism, which were typically seen with Lu You.In Chapters 5 and 6, I discuss how civilian poets (or non-bureaucratic poets) composed the poems on the Huaihe river. In Chapter 5, I consider three poets, Jiang Kui, Liu Guo, and Dai Fugu, and discuss why they went on a journey to the Huaihe River. In Chapter 6, I discuss the poems composed by other civilian poets, which were distinct from those made by bureaucratic poets.In Chapter 7, I mainly discuss the poetry of Huaihe river in the late Son Dynasty and the early Yuan Dynasty, introducing the poems by Wang Yuanling, Li Tingrui and Yin Tinggao, because the role of the Huaihe river as a frontier fort was terminated with the unification of the Yuan Dynasty.The Huaihe river may be considered as a mirror that most symbolically reflects the reality of the Southern Song Dynasty. The poetry of Huaihe river in this era includes negative feelings such as resentment, excitement, grief, sorrow and resignation. All such emotions were repeatedly composed as poems throughout the 150 years of the Southern Song Dynasty. Furthermore, similar poetry was often conveyed to poets who crossed the Huaihe river even after the unification of the Yuan Dynasty.