現今流傳的平仄譜與日僧空海《文鏡秘府論》所記錄的唐代格律資料，在理論思維及表陳方式上皆存在明顯的差距，其間歷經了怎樣的轉折過渡，是吾人理解唐詩格律發展的重要課題。本文透過對於日本詩格《作文大躰》「十則」的研析，尋索出從初唐元兢「拈二」發展到「二四黏對」及近世平仄譜的關鍵進程。文中首先將具體說明《作文大躰》「十則」對於元兢四病的繼承、調聲術的擴充，指出其間的承續關係。其次，藉由其中的口訣「二四不同二九對」、「二四不同二六對」，析論五言「二四黏對」、七言「二四六黏對」的發展過程。再次，論析為了因應平仄二元化的架構，「避病」與「調聲」必須經過協調整合，因而可能朝向減化的趨勢而行。最後，探析平仄譜初立的樣貌及意義，以與近世平仄譜進行對照，並反思格律規範簡化為平仄譜所衍生的問題

There are many obvious distinctions, in terms of theoretical thinking and ways of expression, between the prevalent level and oblique tones at the present time and the metrical patterns in the Bunkyouhifulon (文鏡秘府論) by Japanese monk Kuukai (空海) in the Tang dynasty. Therefore, the transition from the latter to the former constitutes a crucial issue in the development of metrical patterns in Tang poetry. This paper explores the critical transition by examining the writing rules of Japanese poetry of ＂the ten clauses＂ of Zuowen Dati (作文大躰). During this transition, Yuan Jing's (元兢) second-character rule in the early Tang developed into the second- and fourth-character rules as well as the level and oblique tone manuals in the early modern period. From the outset, we explicate how ＂the ten clauses＂ in Zuowen Dati inherited from Yuan Jing's ＂four regulations＂ and expanded on his methods of ＂the alteration of tonal prosody,＂ which explains the hereditary relationship between the two. We also analyze the developmental process of ＂the Nian Dui between the second and the fourth places＂ in five-character verses and of ＂the Nian Dui among the second, the fourth and the sixth places＂ in seven-character verses through the mnemonic phrases - ＂the second and the fourth places differ while the second and the ninth places complement each other＂ and ＂the second and the fourth places differ while the second and the sixth places complement each other.＂ In addition, the poets must strike a balance between ＂the avoidance of mistakes＂ and ＂the alteration of tonal prosody＂ in order to fit into the framework of the binary division of pronunciation into the level and the oblique, possibly resulting in the tendency towards simplification. At last, we discuss the forms and significance of the level and oblique tone manuals in their early development so as to compare them with their early modern counterpart, and to reflect on the issues derived from the transition from the metrical patterns to the level and oblique tones