由對音和當時西班牙和葡萄牙人的書寫習慣(詞頭和詞尾的習慣寫法 和衍變可能)、西班牙人在華行程路線和離開港口(係水陸並用，沿東 江而行，經興寧江、梅溪，穿產溪，進入和頭溪，再陸行然後轉入九 龍江到達漳州府，其後被送往海澄)的考定兩大方面可以證明西班牙 人記載中的「Aytiur」(Aytim)就是海澄港。一旦港口的位置可以確定， 傳教士的記載則可以成為重要的貿易史料：在1567年「開海」後，海 澄與菲律賓的貿易並非立即變得可觀，遲至1580年，從海澄前往馬尼 拉貿易的商船仍頗為有限，方濟各修士遲滯於海澄就是很好的證明。 相比之下，1575年奧斯定修士一行途經的同安和中左所看起來似乎更 為繁榮。這種具體案例相對於冰冷的數據有助於我們理解更形象的歷 史狀況，因為餉稅的收入是對東西二洋總體貿易的不完全反映，而非 對馬尼拉貿易量的反映，馬尼拉方面的統計資料反映的也不僅僅是海 澄甚至漳州的航往船量。1580年其後的一二十年是漳泉兩地為主的生 理人與西班牙人大規模貿易全面展開的階段。海澄的「興起」一定程 度上是督餉館等一系列制度確定的結果。

Based on a phonetic, linguistic, and discursive analysis of sixteenth-century Iberian, “Aytiur” (Aytim) can be confirmed as the port of Hayten (“Haicheng” or “Yuegang” in Chinese). A study of the route which the Spaniards took in Southern China in 1579 (along Dongjiang, Xingningjiang, and Meixi to Chanxi and Hetouxi, then through Jiulongjiang to reach Zhangzhou-Fu) also provides evidence as to Aytiur’s Chinese identity and location. After establishing the exact location and identity, the article next considers extant missionary records to gain a more nuanced understanding of trade in the area. Based on a close reading of primary documents, it seems that trade with the Philippines did not begin immediately following the opening of the port of Aytiur in 1567; in fact, until 1580, there were very few Manila-bound sea-faring vessels leaving the port of Aytiur. At the same time, Augustinian missionaries writing in 1575 reported a great number of ships in the two ports of Tansuso and Tongan, which were both more prosperous than Aytiur. Comparing the statistics of trading vessels and taxation records, this article concludes that the commercial situation in Aytiur was limited in the 1570s and that significant trade with the Spaniards began only in the 1580s or 90s. Aytiur’s growth as an important port city resulted from its location and a combination of institutional changes favorable to trade.