Abstract: Objective: To calculate the nursing workload of general wards based on measurement of nursing working hours,and use the manpower formula to figure out the numbers of nurses which could meet the clinical needs. Method: Totally 16 typical general wards were selected in a tertiary hospital. From June to August in 2013, well-trained observers were arranged to follow the nurses who were on duty and measure their nursing activities in a one-to-one way. Database was established by EXCEL software. SPSS17.0 was used to calculate the unit average time of direct nursing care. And their corresponding average frequencies per day were calculated by Hospital Information System. Other parameters in manpower formula were calculated in light of the law and absence on leave data from nursing department. Finally numbers of nurses theoretically needed in general wards were calculated when all the parameters' values were determined. Result: The average bed nurse ratio of general wards was 1:0.42 by manpower formula, which was higher than the authorized ratio of 1:0.4 from Ministry of Health. Conclusion:Determination of nurse staffing by nursing workload based on measurement of nursing working hours and Hospital Information System is scientific and rational. Different wards have different nursing workload. Unit characteristics, patient diagnosis, work requirements, and workloads should be considered in order to allocate clinical nurses effectively.