「模擬」為漢魏六朝一種重要創作現象，然明、清以降，率視其乏獨創意義，乃貶抑、輕忽之。近年以來，學者已漸能矯正觀念，本文即在此基礎下，深入探討陸機〈擬古〉的重要意義，釐析其在整個模擬傳統中所具有的建構與影響價值；同時探索「模擬」所蘊藏的豐富內涵以及其與經典詮釋、形成間的密切關係。 文分六節，除〈前言〉〈結論〉外，其目分別為〈陸機之前的四種模擬〉、〈陸機擬作與古詩之異同〉、〈陸機之模擬觀〉、〈典律之形成與詮釋〉。撮要言之，陸機模擬於承繼前人之餘，更有所開創—— 蓋技巧益趨精緻深細，風格題材轉為縟麗，情志表現則由十九首之死生之念，一變而為美人遲暮之悲—— 整體而言，陸機模擬不但變古詩為自我內在的呈露，同時亦使民間歌詩體裁雅化為世族貴遊所用，可謂因應上層文人的文化處境而開展出的嶄新詩歌風格。 此一模擬手法進一步呈現的是陸機對模擬的態度與觀點。陸機之前的文人擬作略可分為四種偏向：一為同情共感；二為經典尊崇；三乃文體法式的確立；四則意在導正。陸機於此，有承繼亦有變化。以〈擬古〉與其他相關文獻相互映照，可總結三點陸機對模擬的觀點與態度：一為「曲盡其意」、二為「新曲故聲」、三為「古典尊崇」。此三者相成互用，形成擬作豐饒之價值意涵—— 〈古詩十九首〉的成為經典文本，乃至五言詩的成為經典詩體，陸機〈擬古〉都具關鍵角色—— 從而印證了「擬作」無論在文體的美感規範或經典的形成、詮釋與評價各方面，都有特殊的意義與功能；而魏晉以後，「擬作」仍繼續變創發展，此一課題實大有繼續研究探討之價值。

This essay strives to point the importance of Lu Chi (陸機)’s Nigu (擬古, imitations of “Nineteen Old Poems”) poems and to re-evaluate his contribution to and influence on the entire imitative tradition. At the same time, we examine the rich connotations of imitation and its close connection with the interpretation and formation of the canon. In brief, we show that Lu Chi’s imitations, while certainly borrowing from his predecessors, are innovative: poetic technique has become refined to the point of exquisiteness, style and subject make a turn for the elaborate, and the emotional contents shifts from the concern with the fickleness of life that permeates the “Nineteen Old Poems” to a lament over the passing of one’s prime. Overall, Lu Chi’s imitations not only overhauled the “Nineteen Old Poems” to make them a vehicle for the expression of the inner self, but also helped to refine a form of poetry popular among the general populace into something the upper classes could utilize, thus responding to the cultural situation of the upper class literati and creating an entirely new poetic style. Lu Chi’s imitative technique also reveals his attitudes on and views towards imitation. He both borrowed and built on the imitation tradition. By looking at his Nigu and other related pieces, three things become apparent about Lu Chi’s attitudes on and views towards imitation: he works for a complete expression within the context of a work, attempts to put a new face on an established work, and holds the classical in the highest regards. These three aspects work together to give the imitative work a richness of meaning – Lu Chi’s Nigu plays a crucial role in the establishment of the “Nineteen Old Poems” as a canon, and to a certain extent in the establishment of the five-syllable poem as the standard poetical form. At the same time, this interplay gives witness to the fact that whether it be in terms of aesthetic norms for a poetical form or the formation, interpretation, and evaluation of a canon, imitation has a special meaning and function.