OBJECTIVE To explore the correctness and practicability of microecology methods to prevent endogenic hospital infection. METHODS The pathogenesis of endogenic hospital infection was discussed by microecology theory. And through three classic cases, the diagnosis and treatment of hospital infection by microecology methods were demonstrated. RESULTS Endogenic infection was a result of translocation of normal microbiota in the body under the influence of clinical factors. CONCLUSIONS It is feasible to prevent endogenic hospital infection with microecology methods.