西晉詩壇擬古之風非常盛行，從《詩》、《騷》至樂府古詩，都有大量的仿作。陸機身處於這樣的時代風潮，其〈擬古詩十二首〉頗受時人的推重。但至中唐以降，一般人大多看重原作〈古詩十九首〉，少有人對陸機〈擬古詩十二首〉稱許，這種推崇原作，貶抑擬作的情況，至清朝更加嚴重，李重華《貞一齋詩說》：「病其呆板」，黃子野《野鴻詩的》更批評士衡〈擬古詩〉：「踵前人步伐，不能流露性情，皆無足觀」。筆者以為這一組詩有迥然相異的評價，最需要考慮的當在於原作和擬作之間規範的依違上。所以本文試從內容、修辭技巧和聲律這三部分比較擬作和原作之間的異同，發現士衡〈擬古詩十二首〉在內容、修辭技巧和聲律這三方面都有值得稱善之處，其最大的特色就是：景物的描摹和人物心理刻畫更加深刻細膩，以及文字趨向文人化、典雅化，表現出西晉的文風和時代意蘊。由此可知前人譏士衡〈擬古〉：「句句蹈襲，然去古人神思遠矣」未必是確論，畢竟被鍾嶸喻為「篇章之珠澤，文采之鄧林」的詩作，應該有讓人可以再三回味的地方。

During West Jin Dynasty, initation of classic poetry writing was popular, and a large amount of imitation works were found from Shi, Sao, and class poetry of Yuefu. Living in that period of time, Lu Ji wrote well-recognized NiGuShi (12 Poems). However, after Tang Dynasty, most people regarded the original writing GuShi (19 Poems), and few praised Lu Ji's NiGuShi (12 Poems). This phenomenon of praising the original writing and criticizing the imitation writing became more serious in Ching Dynasty. Li Zhong-hua's Zheng YiZhaiTeShuo described it as “dull”. Huag Zi-ye's YeHongShi criticized NiGuShi as “heeling the footsteps of the predecessors, unable to express one's own emotions, thus, it is lack of values”. The researcher has different comments on the poems, and taken consideration of the norm between the original writing and imitation writing. Based on the comparison of content, rhetoric techniques, and sound rules of the original writing and imitation writing, this study found that Lu Ji's NiGuShi (12 Poems) was worthy praising in all three aspects, and its main characteristics were profound and exquisite depiction of the landscape and character's thoughts, literary and elegant writing style, and expression of the literary style and culture of West Jin. Therefore, the criticism of “imitation of the predecessors but able to depict the thinking” may not be accurate. After all, Lu Ji's poems were described by Zhong Rong-yu as “excellent writing and master with literary grace”, thus, may be worthy reading.