After the outbreak of Sino-Japanese War in 1937, China sought support and sanctions against Japan from the international community, especially the United States. The government strategy encompassed both official diplomatic channels and non-state channels such as propaganda and private organizations. Drawing from materials in the United States and China, this article presents the evolution of China's "public diplomacy" toward the United States during the early years of the Sino-Japanese War. It argues: (1) China's "public diplomacy" was conducted through the International Department of Ministry of Information of the Chinese Nationalist Party under the direct control of Chiang Kai-shek. (2) Resident agents of China played an indispensable role in forming the American Committee for Non-Participation in Japanese Aggression, a private organization supporting China's cause. (3) The Committee carried out intensive campaigns to bring about pro-China policies and to promote an embargo against Japan. (4) The Chinese government and its agents supported the Committee financially and organizationally until its disbandment in 1941. This article thus demonstrates that wartime China was attempting to compensate for its military weakness by manipulating American public opinion to achieve its own diplomatic goals.