1920年成立的大成火災海上保險株式會社，乃日治時期本社設於臺灣最重要之產物保險公司，也是少數由五大家族、各地富商所共同設立的公司。過去關於大成火災的研究，在經濟史方面，多是從公司股東成員之異動，例如臺、日人間的持股比例變化切入，認為此乃臺人資本從屬於日人資本之過程；在家族史方面，則是將大成火災海上視為家族經營、投資的一部分，但並未詳細探討公司內部的經營與人事。有別於過往的研究，本文利用長期擔任公司董事會重要職務，例如林獻堂、益子逞輔等人的相關紀錄，探討自創設以後大成火災內部不斷出現之經營爭執與人事糾紛。本文認為從大成火災的例子中，可以看出日治時期標榜日、臺合作理想的合資公司，其實存在著理想和現實的隔閡與落差，文獻所呈現的人際網絡、公司經營，與重要董事成員的自身感受，說明了日治時期的臺人資本並非單純能以日資的從屬、對立視之，反而是在與日人資本的合作中存在競爭，且不斷地努力調整己身之定位。

The Taisei Fire and Marine Insurance Company, founded in 1920, was the most important property insurance company established in Taiwan during the Japanese colonial era. Moreover, it was among the few companies jointly established by the then five most powerful families and local tycoons. Previous studies from the perspective of economic history focused mainly on the restructuring of shareholding members in this company. For example, changes in shareholding ratio between Taiwanese and Japanese investors were considered a reflection of the growing domination of Japanese capital over Taiwanese investment. From the perspective of family history, Taisei Fire and Marine was regarded by each shardholding member as part of their family business and investments. However, details on its internal operations and personnel have not yet been thoroughly investigated. Through examining relevant records pertinent to key long-tenured board members, such as Hsien-Tang Lin and Teisuke Mashi, this study explored ongoing internal disputes over operations and personnel. The experiences of those involved in Taisei Fire and Marine reveal the existence of a gap between the ideal and reality of corporations purported to be successful Japanese-Taiwanese joint ventures during the colonial era. The networking, company operations, and feelings expressed by key board members recorded in the literature indicate that Taiwanese investment was not subordinated or in opposition to Japanese capital. Rather, Taiwanese investors cooperated and competed with their Japanese counterparts and constantly strived to adjust their own status.