As early as in the second half of the 19th century, bacteria have already been used to treat cancer patients. In 1868, German doctor W. Busch reported that when patients with Sarcoma were intentionally infected by Streptococcus pyrogenes, the tumors were suppressed or eliminated. Later, similar cases of bacterial cancer treatments were reported by American doctor William B. Coley and German doctor Friedrich Fehleisen, independently. However, these early attempts remain controversial due to lack of repeatability and safety. In recent years, systematically designed animal experiments have proved that bacterial treatments can effectively suppress tumor growth and also stimulate immune system of the hosts. In this article, we will try to give out an outline of the history, development and future of bacterial cancer therapy.