It has always been a difficult task to research and transcribe ancient seafarers'terms pronounced in different regional dialects.Since 2015,the author has been trying to mark the pronunciation of seafarers'terms in Hokkien(Southern Fujian dialect)using Chinese Pinyin,and to record them in Chinese characters,but was unable to find a satisfactory solution.In 2017,the oldest and largest extant Spanish-Chinese dictionary was available for study at the University of Santo Tomas Archives.This Dictionario Hispánico Sinicum was most probably compiled in 1626-1642 for missionary purposes in Fujian by Spanish missionaries of the Dominican order with the assistance of Zhangzhou people living in Manila.The dictionary has a total of over 1,103 pages,containing about 21,000 entries,including single words,short sentences,idioms and slangs.From left to right are Spanish entries,Hokkien vernacular in Chinese characters,Hokkien pronunciation transcribed with Latin alphabet,and Mandarin pronunciation noted with Latin al-phabets.The dictionary not only contains many maritime terms,but more importantly,it has e-nough single Chinese characters to be combined into other nautical words.This should solve the problem of how to use Pinyin and Chinese characters to note and write Hokkien dialect,a problem which had persisted for many years.This article not just showcases the oldest existing maritime vocabulary in Hokkien dialect,but also explores the means to write and note the maritime glossa-ries in different regional dialects,with an emphasis on the technical logic behind the terms.The dialect dictionaries compiled by missionaries in the past may contribute to the edition of a compre-hensive maritime technical vocabulary and seafarers'glossary for the various dialect areas along the Chinese coastline.