乐府诗体式研究是对乐府诗文体的专门研究，主要关注的是乐府诗语体、结构、句度、声辞等方面的体式特征。本文通过对乐府诗中对话体、对唱体、套语、声辞合写、三字节奏、五言四句体、声律等体式现象的具体考察，试图揭示乐府诗语言形式与音乐歌舞表演之间的关系，以求对乐府诗体式的形成、功能、意义作出更深入的解释，这是一项现象描述与理论探讨相结合的研究。本文共分四章，第一章是乐府诗的语体研究，主要研究了乐府诗中的对话体和对唱体，认为它们属于乐府诗用作戏剧脚本或演唱底本而形成的特殊的用语方式，受到演艺体制和演唱传统的影响。第二章是乐府诗的结构研究，主要研究了乐府诗中的套语和声辞合写现象，认为套语属于乐府诗因作为口头说唱表演的脚本而形成的特殊的用语方式。声辞合写，是乐工记录歌词的传统方式，主要运用于曲唱文本中，乐府诗中的“声”字往往具有一定的音乐含义和音乐功能，是以文字形式记录乐音的谱字。第三章是乐府诗的句度研究，主要研究了乐府诗中三言节奏所反映的辞乐关系以及五言四句体的演变及其原因，认为乐府诗的句度和音乐节奏、曲调之间有着密切的关联，歌诗字数、句数都要符合乐曲的节奏和旋律从而方便入乐。第四章是乐府诗的声律研究，主要研究了萧齐永明以后迄于初唐声律理论在文人乐府诗中的实践情况，试图阐明人们的新体诗是从乐府歌词里得来了声调与训练，进而论述唐代近体诗形成过程中，乐府诗在声律方面所处的历史地位。通过上述初步研究，我认为乐府诗的原生的状态是一个集聚并且融合着诗歌、音乐、舞蹈和戏剧萌芽等各种艺术样式的综合性艺术体系。乐府诗是演唱传统和演艺体制的必然产物，长期以来的音乐娱乐艺术形成了乐府诗各个层面上的表现功能和体式原理。

The research on the styles of Yuefu-poetry mainly studies the characteristics of styles of the type of writing, configuration, verse, lyrics, and etc. This essay tries to show the relation between the language form of Yuefu-poetry with the dance and music performance, through the investigation on dialog、dialogic sing、formulas、the lyrics being composed with the music letters、the trisyllabic verse、four-line with five-character rhythm of Yuefu-poetry, in order to give an embedded explanation to the formation, function and meaning of the styles of Yuefu-poetry.This essay consists of four chapters. The first chapter focuses on dialog and dialogic sing, which are considered to be special language form used in the drama or singing script, and influenced by the tradition of singing and the system of performance. Chapter 2 studies the formulas and the lyrics being composed with the music letters, considering formulas as a special language form as Yuefu-poetry is regarded as the script of oral performance. The lyrics being composed with the music letters is a traditional way for executants to record lyrics, mainly used in the singing script. “Sheng” in Yuefu-poetry always has some musical meaning and function as music letters to record tone with characters. Chapter 3 mainly studies the relation between lyrics and music, and the development of four-line with five-character, as well as the reasons of the development. There is a close relation between the verse of Yuefu-poetry and its rhythm and tone. The letters and sentences should accord with the rhythm and tone. Chapter 4 mainly studies the application of rhythm theories in Yuefu-poetry from Yongming dynasty to the earlier of Tang dynasty. It tries to illustrate that people who write metrical poetry gets tune and training from the lyrics of Yuefu-poetry, and then to demonstrate the historical status of Yuefu -poetry in the formation of versification in Tang dynasty.Through the above mentioned research, the author considers the original status of Yuefu-poetry is a systematic set of many kinds of entertainments including poems, music, dance and drama. Yuefu-poetry is an inevitable outcome of the tradition of singing and the system of performance. The long-term art of music and entertainment has shaped the functions and styles of Yuefu-poetry in every aspect.