東沙群島，又稱浦拉他士島。東沙群島位於南中國海的東北，由東沙島、北衛灘及南衛灘所組成。早於一千年前，東沙島已記錄於中國古籍中。東沙島附近海域為中國漁民捕魚區。1908年，日本商人西澤吉次占領東沙島，為了建設東沙島為鳥糞與漁獲的收集區，西澤吉次毀掉華人所建之廟宇，挖掘華人的墳墓及將骨頭棄入海中。他為東沙島取名為西澤島。廣東政府派遣軍艦前往東沙島，及在日本東京及廣州，經過中國與日本的外交交涉後，1909年，中國重新確保對東沙島的主權，西澤吉次亦從廣東政府取得賠償。本文分析中國與日本的外交交涉過程及說明其影響。

The Dongsha Islands, also called the Pratas Islands, are located in the northeastern South China Sea. They consist of Dongsha Island, North Vereker Bank and South Vereker Bank. Records of the Dongsha Islands are in Chinese ancient texts dating back more than a millennium. Chinese fishermen fished in the sea around the Dongsha Islands. Nishizawa Yoshizi, a Japanese businessman, occupied the island in 1908. In order to establish Dongsha Island as a guano and fish collecting station, Nishizawa Yoshizi destroyed a temple building, dug up the graves of Chinese fishermen, and threw their remains in the sea. Nishizawa Yoshizi renamed the island ‘Nishizawa Island’. Finally, after two Chinese naval vessels were dispatched to the islands, and following diplomatic efforts in Tokyo and Guangdong, China re-established its sovereignty over them in 1909. Nishizawa withdrew from the island and received compensation from the Guangdong provincial government. This article summarizes and analyzes the process of the diplomatic confrontation between China and Japan and its effects.