From the beginning of the 19th century to the Opium War, by taking the advantages of free entering and departing China, and to protect themselves, the foreign firms introduced vaccination technique into China. This is the beginning of the introduction of western medicine to China. After 1807, following the arrival of protestant missionaries, foreign firms became the stronghold for the missionaries to conceal their missionary status so as to propagate the principles of Christianity. With the aid of the business firms employee's legal identity, the missionaries started their activities of delivering western medicines and practices. Later, the business firms gained commercial profits through the subsidizing medical services and infiltration. Although western medicine objectively improved the medical conditions in China and promoted the modernization of Chinese health career, but it cast an important aspect of western aggression against China at the same time.

British East India Company; Foreign firms; Medical missionary; Medical exchange between China and foreign countries