Background: Tobacco hazard is known as one of the most critical public health problems. Nurses could and should help patients to quit smoking. However, the lack of tobacco cessation education of nurses at medical school leads to the absence of behaviors helping smokers to quit. The analysis of the factors that influencing the nursing interns to help smokers to quit provide evidence for nursing school to administer tobacco cessation education to facilitate more behaviors of smoking cessation in future nurses.Method: To explore the interaction and the effect coefficient among the influencing factors of the 5As behaviors of nursing interns in helping smokers to quit provide and to provide evidences for the tobacco cessation education, a questionnaire based on the PRECEDE theory was developed with consideration of predisposing factor, enabling factor and reinforcing factor. Random Cluster Sampling was used to conduct a survey in 13 teaching hospitals selected from 29 in Chongqing to assess the 5As behaviors of all nursing interns. A structural equation model was established to test the path and effect coefficient of their 5As behaviors.Results: The survey investigated 1358 nurses, and the model fitted well with the data. The tobacco cessation education, one of the enabling factors, imposed max effect on the 5As of nursing interns directly(β=0.542,p<0.001) and indirectly(β=0.38,p<0.001)through self-efficacy. The reinforcing factors ( smoking cessation environment) imposed direct effect (β=0.305,p<0.001)and indirect effect on the 5As of nursing interns through attitude changes. Predisposing factors including self-efficacy influenced the 5As directly, while attitude(β=0.001,p<0.05)and knowledge(β=0.008,p<0.05)of tobacco cessation implied indirect influence on the 5As through self-efficacy change. Conclusion: Tobacco cessation education was the major factor that influenced the nursing interns’ behaviors of helping patients to quit smoking. Enhanced responsibility of smoking cessation education and skills training of clinical teachers can prompt them to actively help patients to quit smoking, actively instruct students the knowledge and skills of smoking quit to increase students' behavior of helping smokers to quit.