Collected 2218 medical records of cerebral infarction patients from 2007 to 2008 in a third-class hospital in Tang Shan as sample. A statistical analysis was made of the hospitalization expenses and its influencing factors by BP nerve network model to identify the factors affecting hospitalization expense by using BP nerve network model. The results showed that the major factors impacting the hospitalization expense included age, hospitalization day, therapeutic result and emergency medical treatment. The sensitivity were: age is 0.91426, hospitalization day is 0.32131, therapeutic result is 0.19722, emergency medical treatment is 0.27564. BP nerve network model is a powerful analytical tool for hospitalization expenses and its influencing factors analysis.