本文主要以歷年＜中華民國海關華洋貿易總冊＞中有關蒙自海關進出口貿易資料 ，分析近代以來雲南對外貿易口岸與交通開放的情形，及探討雲南近代以來經濟的發展及變 化，並分期說明其特徵。 蒙自海關的開埠，使雲南開拓了新的經濟出路，對雲南帶來了良性刺激，推動雲南的現代化 之路。而滇越鐵路的開通，也聯接了中國昆明與越南海防，開闢了雲南的出海孔道，使雲南 與中南半島更加緊密地聯繫在一起；並使得雲南在中國與東南亞的經濟交往中，佔有舉足輕 重的地位。 這也說明了鐵路使雲南由省內商業交易型態，擴大為省際貿易及國際貿易；尤其是貿易流通 路線的轉移，更加明顯的由北轉而往南，並大幅成長，這是在蒙自海關未開埠及鐵路未完成 之前所沒有的現象。

　　　　　The theme of this paper concerns information on the trade imports and exports of Mengtsz (蒙自 ), and an analyzation of Yunnan's situation in modern foreign trade and its opening of communications; it also explores Yunnan's modern changes and its developing economy. Using periodical characteristics to fully explain. The establishment of Mengtsz Customs opened a new economic road for Yunnan and enabled it to expand; this economic stimulant in turn pushed Yunnan's economy into the modern era. Another important factor was the opening of the railroad between Yunnan and Vietnam, wihch linked China's Kunming city and the city of Haiphong in Vietnam, and connected Yunnan with a sea port. Because of this railroad; the economic relationship between Yunnan and Indo China become very important to both. This paper also explains how the establishment of Mengtsz Customs and the railroad transformed the province of Yunnan from a provincince type of trade into an inter-province and even international type; especially evident is the movement of the trade routes from the north to the south and their there after grows rapidly all corelating with the establishment of Mengtsz Customs and the railroad.