The "on-duty systems" and "dispatching systems" in the Tai yi yuan (Imperial Academy of Medicine) of the Qing Dynasty served as the "prelude" of the medical officials to carry out their diagnoses and treatments. Mainly serving in the royal court, the "on-duty systems" included 3 sorts, viz., "specially selected on-duty", "interior on-duty" and "exterior on-duty". In addition to providing medical services in the royal court, Imperial Academy of Medicine also served other royal members in the Capital, the ministers, the military, the civilians, the metropolitan examinations and the prisons. Thus, the "dispatching systems" was established, also included 3 sorts, viz., "special dispatchments", "dispatchments through reporting to the emperor" and "dispatchments through official communication".