Learning how to effectively respond to ethical dilemma can affect nurses’ physical and mental health, which is not conducive to developing a nursing career. Nursing students’ ethical behavior warrants attention as professionals about to begin clinical work. We aim to understand the current situation and influencing factors of Chinese nursing students’ ethical behavior. A cross-sectional descriptive study was conducted. Descriptive statistics and multiple linear regression were used to analyze the data. Full-time nursing students were recruited from an undergraduate medical university in Jinan through convenient sampling from November to December 2021. Research ethics approval (No. 2022-0018) was obtained from the Ethics Committee of Affiliated Hospital of Shandong University of Traditional Chinese Medicine. Informed consent was also received from participants. The EBT scores of the nursing students were 95.14 ± 11.37, which was not high compared with the total score. Gender, year level, and professional values had a significant impact on participants’ ethical behavior. A positive correlation was found between nursing professional values and ethical behavior. A gap still exists between the moral development and maturity of undergraduate nursing students. To further cultivate their ethical behavior and improve their confidence and ability to respond to ethical dilemmas, more innovative methods must be employed in teaching ethics courses, and continuity in the ethics education system must be maintained. For male and third- and fourth-year nursing students who showed lower ethical behavior scores, nursing educators can develop their ethical behaviors by helping them establish positive professional values.