Objective To evaluate nursing efficiency in hospital and its influencing factors, and to provide reference for improving clinical nursing efficiency. Methods The data on nursing service, nursing quality, nursing teaching and research of 44 nursing units in two hospitals in Jiangsu province and Yunnan province were collected, which were then evaluated using the data envelopment analysis model, and the Tobit regression analysis model was used to explore the influencing factors. Results The average efficiency of nursing service, nursing quality and nursing teaching and research in each unit was 0.695, 0.697 and 0.438. Tobit regression analysis showed that, bed utilization rate, nurse-patient ratio, ratio of nurses above the professional title of junior nurses, ratio of nurses above bachelor degree, and actual number of nurses on duty were the influencing factors of nursing efficiency (P＜0.05,P＜0.01). Conclusion The overall nursing efficiency in clinical nursing unit is not high. Managers can improve the overall efficiency of the nursing unit through raising the bed utilization rate, increasing nursing human resource and the proportion of nurses above ju-nior nurses, and optimizing the nurse-patient ratio, etc.