租借區的英文報是中國報界的重要組成部分。然而這種媒體形式在學界一直被認為是殖民者的喉舌而未被納入到中國新聞界的考察範圍。租界區媒體通常具備多國背景且互相競爭激烈。而正是這一難以掌控的媒體，成為國際宣傳資源匱乏的南京國民政府寶貴的對外宣傳資源。本文首先考察租界區英文報界複雜的媒體環境，而後討論國民黨政府在中日全面戰爭爆發前對此媒體的管制和滲透。面對租界區媒體身分模糊，信源隱蔽的狀態，國民黨各部分勢力亦順從這一趨勢，在潛入租界區英文報界以及爭奪英文媒體資源的過程中，隱藏黨派背景以求保持信源的可信度。同時，這一過程為中國日後開展國際宣傳積攢了廣泛的人脈網絡，並為董顯光在中日戰爭全面爆發後所推廣的隱性宣傳政策打下了堅實的基礎。

The treaty-port newspapers played an important part in China's press history. Considered as mouthpieces of colonial empires, however, they haven't been recognized as part of China's press worthy of scholarly attentions. Typically with multi-national backgrounds and intensely competing with one another, these English-language newspapers were the kind of media hard to control, which naturally made them valuable outreach resources for the Nanjing KMT government with its international propaganda purposes to serve. Intrigued by this particular role played by these treatyport newspapers, the essay examines first the complicated media environment for their operations. It then explores how the Nanjing KMT government endeavored to regulate and penetrate these newspapers before the outbreak of the full-scale Sino-Japanese War. Characterized by their ambiguity in media identity and the obscurity of their news sources, these treaty-port newspapers somehow influenced those KMT officers who sought to voice through them. Various KMT groups and factions tended to conceal their party links and factional identities in order to secure smooth penetrations. Such penetrations not only greatly expanded the Nanjing KMT government's information contacts and networks, but also laid the foundation for the covert news policy endorsed by Hollington Tong after the outbreak of the full-scale Sino-Japanese War.