Objective To investigate the current status of perception of patients' safety ability and its influencing factors among undergraduate nursing undergraduates.Methods A total of 732 undergraduates from seven regions of China were selected by convenience sampling and the Health Professional Education in Patient Safety Survey（H-PEPSS）was used for investigation.Results The total score of H-PEPSS of nursing undergraduates was（61.20±9.63）and（64.09±9.09） in the classroom and clinical practice versions,respectively. There was a significant difference between them（t=2.61,P<0.001）.Multivariate linear regression analysis showed that self-evaluation ability of patient safety,patient safety training courses participation,whether making mistakes during practice were the influencing factors of patient safety ability level perceived by undergraduates in classroom and clinical practice which accounted for 13.0% of the total variance.Conclusion The low level of perception of patient safety ability of undergraduates,which needs to be further improved. There is a gap between the students' perception of patients' safety ability in classroom and clinical practice. In the classroom and clinical teaching,nursing educators should pay attention to the cultivation of patient safety knowledge,skills and self-confidence,and focus on students who have made mistakes.