Objective：To establish the control range of the monthly nosocomial infection incidence for intensive care unit（ICU） and to offer a scientific method for controlling nosocomial infection. Methods：Based on the statistical theory of medical reference range：value falls in the region of the warning limit is less than the probability of 95% for the area under the normal distribution curve. If the value exceeds the limit，attention should be paid by the clinical department. While the value falls in the region of the control limit is less than the probability of 99% for the area under the normal distribution curve. If the value exceeds the limit，it indicates out of control. Target monitoring data of respiratory ICU，neurology ICU，comprehensive ICU，neurosurgery ICU，cardiothoracic ICU from January 2011 to June 2012 were separately collected to establish the warning limit and control limit of the monthly nosocomial infection incidence. Nosocomial infection incidences of these ICUs since July 2012 were compared with the warning limit and control limit to find out the abnormal values. Feedback was returned to the units when the value exceeded the warning limit. Intervention was made when the value exceeded the control limit. Results：The warming limit and the control limit of monthly nosocomial infection incidence for dif－ferent ICU had been established. The control limit of monthly nosocomial infection incidence for neurosurgery ICU was 22.39%. Nosocomial infection incidence of neurosurgery ICU exceeded the control limit in August 2012. Nosocomial infection incidence of neuro－surgery ICU decreased the following three months after analysis，feedback and intervention. Conclusions：Establishing control range of the monthly nosocomial infection incidence is recommendable since it can warn the tendency of the nosocomial infection，assess the nosocomial infection incidence levels of different ICUs and ensure the continuous quality control.