光緒34(1908)年，日本商船二辰丸運載軍火，停泊在中國東南海面等待買方接應。後來，二辰丸遭到廣東水師盤查、扣押，是為事件之濫觴。隨即，日本外務省要求北京外務部必須馬上歸還船隻、賠償損失，及嚴懲地方失職人員。外務部欲將此地方涉外事件，直接交由廣東與日本駐廣州領事就地解決即可。惟兩方立場不一，認知差距大，引發爭論。最終，外務部介入其中，主動對日交涉，以弭平爭端。 外務省援引國際法、戰爭法，抗議廣東水師擅自撤下船上懸掛的日本國旗，侮蔑日本，要求外務部必須歸還船隻、謝罪道歉、賠償損失與嚴懲禍首。然而，外務部汲取多方意見，認為廣東撤旗之舉有嚴重疏失，決定先歸還船隻與對日示歉；然外務部並非完全妥協，反倒堅持中國領海權與查緝軍火走私之權利，賡續談判。 領海問題方面，日本、葡萄牙視澳門為葡屬地，以喀羅灣為葡屬領海，廣東無權於此扣押船隻。對此，外務部宣示船隻停泊喀羅灣東部係屬中國領海，又引《中葡條約》斥責葡萄牙肆意擴展澳門勢力範圍。軍火問題方面，日本要求軍火同船隻歸還，惟廣東以軍火走私確已嚴重危害地方治安，不可妥協，若開惡例則後果嚴重。最終，外務部決議由廣東收購軍火平息糾紛，並藉此換取日本允諾，協助杜絕走私軍火赴澳門。 晚清列強在華走私軍火猖獗，二辰丸事件不僅引起中日間的爭議，更成為列強關注的焦點。外務部化解危機後，與日本達成杜絕軍火走私澳門之共識，且透過此模式請英國禁絕香港軍火走私，更主動與各國簽定《改訂槍彈進口新章》，藉此條約規範外國在華走私軍火。除此之外，外務部在事件落幕後與葡萄牙勘查澳門界址，進而設置軍隊駐防，鞏固中國對澳門的控制權及領海權。

In 1908, the event source that the Japanese merchant boat, Tatsu Maru, anchored southeast sea of China, then encountered detains. The Japanese Ministry of Foreign Affairs set requests to the China Ministry of Foreign Affairs for returning the boat, compensating the lose, and punishing the dereliction of duty personnel. The latter planned to solute the point of contention according to the place consultation and stops the even conflict. But the former rejected it. From now on, they start the negotiations. In the end, the China Ministry of Foreign Affairs gave Tatsu Maru back to Japan, and expressed the apology for removing the flag of Japanese. Nevertheless, the China Ministry of Foreign Affairs made the grade. First, Qing Government and many Countries signed the treaty to prevent the munitions smuggling. Second, after Qing Government examining the border of Macao with the Portuguese official stationed in China, subsequently took back many loses, and dispatched troops to station. Third, Qing Government prevented ahead of time, and had not paid a large amount of compensations to Japan. In brief, we must face up the negotiations of the China Ministry of Foreign Affairs was a great achievement.