本文以臺灣西南部沿海的浮覆地──臺江海埔的開發為取徑，探討以臺灣郡城為地緣核心的官商利益結構，及其對清代後期臺灣政治的影響。 自清初以來，臺灣西南部沿海浮覆地因可從事築塭養魚或開埕曬鹽等事業，其土地開發早就成為知縣、衙役與地方有力者共同獲取利益的領域，有力者以報納塭餉為手段，取得海坪、海埔，築塭養魚，知縣則徵收塭餉但不奏銷，兩者互取其利。道光三年（1823），曾文溪氾濫造成臺江內海浮覆，該浮覆地鄰近郡城，且面積廣達 5,000甲以上。臺灣道員以籌措清理軍工廠港道經費為由，將此浮覆地交給以郡城紳商為主的墾戶開墾，並徵收包含稅及租金性質的海埔租，使這片墾地脫離國家賦稅行政的管轄，成為道員、管事與郡城紳商彼此互惠的利益結構之一環。 由道員與郡城紳商為主體的利益結構，不僅涉足臺江海埔的土地開發，也包含樟腦專賣、生息銀兩、義倉管理等各方面。此利益結構的形成，有助於道員開闢非正式經費來源，雖不乏中飽私囊者，但也有道員將此資源投入各種地方建設，彌補地方財政不足。到了光緒十年（1884）前後，道員劉璈（?-1889）與劉銘傳（1836-1896）展開政爭，原有郡城官商利益結構因而遭受打擊，影響力趨於沒落，代之而起的是劉銘傳與臺灣中、北部紳商相結合的另一個利益更龐大的官商利益結構。

Focusing on the Tai-jiang reclaimed land in the southwest coastal area of Taiwan, this article examines the government-business interest structure of Taiwan prefecture and its influences on the political development in Taiwan in the later period of Qing dynasty. The exploitation of reclaimed land in the southwest coastal area of Taiwan had been a field entangled with power struggles and interest competition since the early-Qing dynasty. Because the reclaimed land consisted in sites suitable for aquaculture and salt production, the local government officials and powerful local figures cooperated to gain benefits from the exploitation. While the powerful local figures got the coastal beaches to develop their aquaculture business by paying the brackish water pond tax, the local government officials got these local taxes under the table, getting rid of the accounting system of provincial expenditure. The Tai-jiang reclaimed land, which was more than 4,850 hectares, was a significant example. It appeared nearby the prefecture because of the flooding of the Tseng-wen River in 1823. The Taotai, the superintendent of Taiwan, opened it for exploitation by local gentries and imposed the “reclaimed tax” by reason of clearing the port of a military factory. Consequently, the vast land was placed out of the national administration and entangled with interest competition. The interest structure of Taotai and prefecture gentries existed not merely in the exploitation of the Tai-jiang reclaimed land but also in the businesses of camphor monopoly, banking, and relief granaries. For the Taotai, such interest structures contributed to the informal funds which could improve the poor local financial conditions, though some officials took money for private use. The interest structure operated until about 1884, when the power struggle between the Taotai, Liu Ao, and Liu Ming-chuan arose. Another larger-scale interest structure constituted of Liu Ming-chuan and gentries in central and northern Taiwan emerged and played a more influential role.