明代中後期私修國史之風盛行，鄭曉（1499-1566）《吾學編》屬發其端者，於明代史學居承先啟後之地位，然這方面研究仍相當缺乏，故本文以明代史學家鄭曉及其著作《吾學編》為研究對象。 本研究透過文集、年譜來探究史學家鄭曉之生平及仕途經歷，並經由整理、爬梳鄭曉《吾學編》、《今言》等著作，來分析其史學思想與內涵。研究後發現：鄭曉一生善於博覽、學貴有用，因仕宦之便，得以閱歷官府所藏故牘，成為私修國史的重要材料；其次鄭曉對史料內容有一定程度的甄別、判斷，開明代徵實史學濫觴，以〈名臣記〉成就最高；復爰因鄭曉學行清正、秉筆公允，故《吾學編》對人物之評價屢受當時及後世讀者的肯定。 鄭曉私修國史，顯示出明代官修史學的侷限，其中以對政治禁忌的處理最能凸顯兩者間之差異。以明初「靖難之役」為例，官方的宣傳內容與敘事方式，往往悖離史實、模糊真相，致叛逆變節者未受指責，慷慨就義之士卻遭詆毀，嚴重扭曲價值觀。對此，鄭曉繼承前輩史家之努力，著力於建文朝史事及人物傳記之書寫，充分發揮史學家道德良知與私家著述較不受官方意識型態限制的優點。 本研究揭示史學家鄭曉及其著作《吾學編》於明代史學史上的意義，然部分內容猶有再進一步討論的空間，未來應持續修訂與改正，以利本文品質之提升。 In recent years, there has been a dramatic proliferation of historical research concerned with the Ming dynasty (AD 1368-1644), especially on historiography. The related works reported in the literature can be classified into two major categories. They are the studies on historians and the historical writings by stages of the Ming dynasty. Cheng Hsiao (AD 1499-1566) is the first writer to attempt a comprehensive history of the Ming dynasty up to his time, but unfortunately only a few isolated recent efforts have continued to address him. Common sense seems to indicate its importance, and the purpose of this research is to present its evidence. The instrument consists of Cheng Hsiao’s chronicle, corpus, notes and etc. The results showed that Cheng Hsiao always took the opportunity to study the documents in the archives and wrote articles of historical records. As noted previously, he was well versed in the history of the Ming dynasty. That Cheng came to be so highly esteemed by the scholars of later generations is because his writings show not only his interest in current developments, but also his keen insights and his historical perspective. Just one example for the article about “jing-nan-zhi-yi” (靖難之役) should suffice to illustrate. However, there has been much emphasis of his historical writing in “ming-chen-ji” (名臣記) of “wu-hsueh-pien”. One explanation for this is that Cheng carried forward the fore historian’s research patterns. These findings are in line with previous studies, although no previous study has asked this question in detail. Future research is obviously required, and the article is subject to constant revision and changes in order to be improved.