本文以指出古典律詩聲律和句法──語義結構中存在同一模式為出發點，進而論證︰中國古典律詩形成中有一超越技術和漢語本體決定性的歷史觀念背景。在魏晉時代音樂觀念之滲入文學的條件下，詩歌被認為如音樂那樣以其抽象的語言形式體象宇宙；同時，以王弼易學為代表的新宇宙觀念則不再強調以「同類相從」的原則，體象出宇宙的包羅萬有的感性形象，而強調擬範出「異類具存」宇宙的變化影跡。「命呂者律」，「命宮而商應」乃此變化中之基本法則，也理所當然地成為聲律結構中「宮羽相變」和對仗的語義結構中「反對」法則的依據。上述概念背景使律詩的形式體認出古代中國人心目中平衡、和諧、沉穩，迴宛的世界秩序。其與音樂觀念的淵源關係則解釋了其美學意味中的超越參指性層次的存在。由此，中國古典律詩即表現為一種渾涵闊大與精微謹細結合之美學境界。

　　　　　This essay starts with indication of a model existing identically for both the metrical and the syntactico-semantic structures of Chinese classical regulated poetry. I go on to argue that the formation of regulated poetry stems from a historical background of ideology which transcends the technical conditions and intrinsic characteristics of Chinese language that people have usually postulated. Since musical concepts had permeated literature in the Wei-Jin period, poetry was regarded as an art which, like music, could embody the cosmos by its abstract linguistic forms. Meanwhile, the new cosmological concepts represented by Wang Bi's (226-249) reinterpretation of The Classic of Changes no longer laid emphasis on the representation of the figurative image of the all-embracing cosmos by the principle of “things mutually influencing according to kinds.” Instead, this new philosophy undertook to trace the perpetual movement of the cosmos in which “things exist variedly.” The basic laws of the cosmic movement are that “what evokes yin pitch is yang pitch” and that “what resonates gong-tone scale is shang-tones;”accordingly, these laws became the very ground of the new metrical and semantic structure of antithetical parallelism. The aforementioned conceptual background confirms that the generic form of regulated poetry embodies the counterpoised, harmonious, steady and perennial order of the cosmos in the ancient Chinese mind. The two conceptual sources also combined to produce the particular aesthetic realm of this poetry, which unifies the mightiest feeling of cosmic vastness with a meticulous sense of mathematical wisdom.