Objectives: "Clinical Internship" is an important course for nursing students to learn nursing specialties and skills. Teaching methods, strategies and attitudes of clinical nursing teachers are key elements to the learning effect of nursing students. The purpose of this research is to investigate the current teaching self-efficiency of clinical nursing teachers and to explore the relevant factors affecting clinical teaching effectiveness. Methods: This study took a cross-sectional survey of clinical nursing teachers. A total of 206 questionnaires were collected by hardcopy and internet questionnaires. Independent t test, one-way ANOVA, and multiple regression analysis were used to describe the differences and identify impact predictors. Results: Results of this study showed that the ability to use professional skills was the best teaching self-efficiency, and the ability to help nursing students learning was the worst teaching self-efficiency. Besides, the age, education degree, highest nursing education degree, nursing academic institution, clinical teaching work experience and workplace stability of personal background variables for clinical nursing teachers had statistically significant differences on the teaching self-efficiency. Conclusions: Results of this study maybe the references for the clinical nursing education reformation and the nursing teachers' training in the future.