應酬詩是指詩人與他人交往時因人際互動需要而寫作的詩篇，包括送別、迎接、酬答、贈送、唱和及宴席上的吟詠之作。本文的寫作目的，不在探討應酬詩的文學之美及價值，而是透過應酬詩將「人、事、時、地」說清楚的特質，觀察它在古籍整理上的價值。 本文運用唐代大曆詩人的應酬詩，分別從「考察作家身世」、「考察作家交遊」及「補充史籍闕漏」三方面，考證出郎士元的生平、重塑盧綸摯友的名單及補充唐大曆三年歷史失載有關赴新羅冊封使的細節。由此可見，應酬詩除了可作文學欣賞的文本之外，也是整理古籍時可賴以考證的有力線索。

Social appointment poem is a kind of poem, written by poets who interacted with others, which included farewell, welcome, response, sing-along, as well as the chant at the party. The objective of this article is not just to investigate the beauty and the value of the social appointment poem in the literature, but through the unique character of the clear description for “people, matter and time” in the social appointment poem, to observe its value on reorganizing the ancient books. This article has taken the social appointment poem poets during Dali period at Tang dynasty, from “the investigation of a writer’s life”, “the investigation of the good friends of the writer”, and “fill up the missing part of the ancient books” three aspects. to prove the life of Lang, Shi-Yuan, to reconsider the best friends around Lu, Lwen; and find out the gap in the history of Dali year three, regarding the detail of going to Hsin-Low for assignment as an ambassador. Above all, we may see the value of social appointment poem is not only on the literature appreciation, but also a powerful clue on reorganizing the ancient books.