大历时期，江南诗人群在时代原因下寓居江南，因为避乱和仕途的需要不断辗转流寓于南方各地，形成较为显著的流寓心态。这种流寓心态在江南诗人的诗歌中又主要表现为孤独感，在孤独感郁结的状态下，诗人将孤独倾泻在诗歌中，借助诗歌的世界表达孤独感。

第一章从诗人于外部环境中感到缺失的体验出发探究诗歌中孤独感的成因。仕宦江南的诗人仕途潦倒，从中体察到不同于前代的时代环境，入仕的理想逐渐失落。羁宦的生涯又造成诗人长期的流寓离乡，流离失所，于是在旅宿诗中写下孤独感浓烈的诗篇。在个人认知上，江南诗人时常以“客”自居，常在流寓途中转身瞭望山水，将山水中的万物点化为“孤客”的代表，深化诗歌中“客”的形象。同时，孤独的凝视体验又影响着诗人对山水的审美感受，将山水塑造为静态且凝滞的样貌。

第二章关注诗人因在人群中感受到疏离而产生的孤独感。江南诗人因流寓时常面临远亲别友的境况，对于回归人群的渴望让诗人倍感孤独，在相逢际会时衍生出或谨小慎微、或畅意感怀、或快然自得等多种细微情绪。当诗人身处人群时，也会偶尔体会到疏离于人群中大多数的感受，写出因对长安、对远方的思怀而感到孤独的情感体验。江南诗人时常在诗歌中写到与他者“共感”孤独，他者有时是人，有时是山川风物。当诗人与他人“共感”孤独时，孤独的感受可以得到略微的排遣；当诗人与山川风物“共感”孤独时，孤独的体验就变得更为深沉厚重。

第三章摒弃外部环境与人群，探究诗人独处时的孤独感。当诗人独处时，他们越发细致地审视自我，咀嚼孤独的境况，营造出属于自我的孤独诗境。江南诗人在诗歌中自觉地书写“掩关”行为，借其象征内心封闭的孤独感受，同时也表达对通往独处闲逸境界的渴求。除此之外，江南诗人还热衷于塑造场景中的孤独自我，最为明显的便是诗歌中的夕阳和夜晚场景。夕阳在江南诗人笔下呈现出悲伤阔大的样子，夜晚则显示出以“清”为主的清苦、清冷、清淡、清沉的面貌。

最后，江南诗人的孤独感书写丰富了我们对孤独感的认知，可以看到孤独感内部蕴藏着许多细腻的情感体验与情感认知。江南诗人的孤独感也串联了大历诗歌的主题取向，从孤独感出发可以看到各类诗歌主题的影子。从诗歌史来看，江南诗人的孤独感是大历人敏感内索、私密自我的一面，是中唐诗歌逐渐走向内在的先导。

During the Dali period, Jiangnan poets lived in Jiangnan for the reasons of the times.
Because of the need to avoid chaos and official career, they constantly moved around and lived in all parts of the south, forming a more significant exile mentality. This wandering mentality is mainly manifested in the loneliness of poets in the south of the Yangtze River. When the loneliness is depressed, the poet pours loneliness into his poetry and expresses his loneliness with the help of the world of poetry.
The first chapter explores the causes of loneliness in poetry from the experience of the poet’s lack in the external environment. The poets in the south of the Yangtze River had a poor official career, from which they realized that the era environment was different from that of the previous generation, and their ideal of becoming an official was gradually lost. As a result, the poet lived in exile and left his hometown for a long time, so he wrote a poem with a strong sense of loneliness in his travel poetry. In terms of personal cognition, Jiangnan poets often regard themselves as “guests”, often turn around and look at the landscape on his way to his residence, turn everything in the landscape into the representative of “solitary guests”, and deepen the image of “guests” in poetry. At the same time, the lonely gaze experience affects the poet’s aesthetic feeling of the landscape, shaping the landscape into a static and stagnant appearance.
The second chapter focuses on the poet’s loneliness caused by feeling alienation in the crowd. Jiangnan poets often face the situation of distant relatives and friends because of their exile. The desire to return to the crowd makes the poets feel lonely. When they meet, they derive a variety of subtle emotions, such as being cautious, feeling happy, or complacent. When the poet is in a crowd, he will occasionally feel alienated from most of the crowd and write about the emotional experience of feeling lonely because of his thoughts on Chang’an and the distance. Jiangnan poets often write in their poems that they feel loneliness with others, sometimes people, sometimes mountains and scenery. When the poet and others feel lonely, the feeling of loneliness can be slightly relieved; When the poet and the scenery feel loneliness, the experience of loneliness becomes more profound.
The third chapter abandons the external environment and crowd, and explores the poet’s loneliness when he is alone. When poets are alone, they examine themselves more and more carefully, chew the lonely situation, and create a lonely poetic environment of their own. Jiangnan poets consciously write the behavior of “covering customs” in their poems, which symbolizes the lonely feeling of inner closure, and also expresses their desire for the realm of solitude and leisure. In addition to this, Jiangnan poets are also keen to shape the lonely self in the scene, the most obvious is the sunset and night scene in the poem. The setting sun presents a sad and broad appearance in the works of Jiangnan poets, and the night shows a bitter, cold, light and clear face dominated by “Qing”.
Finally, the loneliness writing of Jiangnan poets enriches our cognition of loneliness. We can see that there are many delicate emotional experiences and emotional cognition in the interior of loneliness. The loneliness of Jiangnan poets also connects the theme orientation of Dali poetry. From the loneliness, we can see the shadow of all kinds of poetry themes. From the perspective of poetry history, the loneliness of Jiangnan poets is the sensitive, introverted and private side of Dali people, and it is the guide for the poetry of the middle Tang Dynasty to move inward gradually.