孫元衡（1661?-?) 於康熙44年（1705) 三月末來臺，至康熙47年（1708) 秋天離臺，擔任臺灣府海防同知，《赤嵌集》便是他在臺灣將近四年，將感觸聞見形諸吟詠的詩集。在閱讀《赤嵌集》之前，我們首先要理解孫元衡來臺所擔任的職務工作。由於孫元衡擔任的是海防同知的職務，因此他常要往返赤嵌與安平之間，因為工作的關係，他所見到的臺南城也異於一般人所看到的景象。到底「海防同知」的職務屬性為何，孫元衡如何將日常生活吟詠成詩，以及孫元衡在執行工作時，在詩中如何呈現出擔任海防同知的感受。本文先詳述清初臺灣海防總捕同知的實際工作內容，再討論《赤嵌集》中有關海防同知的職務書寫，最後則以實際詩作，探討《赤嵌集》中呈現出幽微的宦情。從這三個角度切入，冀望能探索孫元衡來臺任官的處境與心境。

Sun Yuanheng 孫元衡(1661?-?) , arrived in Taiwan to be served as sub-prefect of Taiwan Prefecture 台灣府海防同知 during the early years of the Qing Dynasty form the year of Kangxi 44(1705) to Kangxi 47(1708) . The sub-prefect was the officer in charge of national defense and security for Taiwan. His four volumes of poetry, known as the Chi Kan Collections 赤嵌集, is the product of his experiences during this four-year period. Chi Kan Collections is the best well-known lyrical work during the era of Kang-his reign, but the investigate of this writing and Sun Yuanheng was deficient till the present. Sun Yuanheng as a mandarin, we will wonder about what is his really assignment in his post during the official life. In this essay, aside from discussing the tasks and agendas of sub-prefect, we will display the circumstance and the mental state of Sun whom be regarded as the significant poet of Taiwan.