The aims of this study was to provide basic data to enhance the professional self-concept of nurses in intensive care unit and identify the relationship between job stress, working bullying, self-efficacy and professional self-concept and identify the factors influencing professional self-concept in intensive care unit nurses. Methods : This study was conducted from June to August, 2018 at five general hospitals over 500 beds. Structured questionnaire were completed by 120 nurses who had agreed to understand and participate in the study. The collected data were analyzed using the SPSS win 24.0 program. Results : Factors affecting the professional self-concept of the subjects were self-efficacy, working bullying, unsatisfaction and satisfaction of nursing job satisfaction, age. The explanatory power of these variables on professional self-concept was 55.1%. Conclusion : The self-efficacy, working bullying, nursing job satisfaction, and age of the intensive care unit nurses were identified as the major factors influencing the professional self-concept. Therefore, it is necessary to develop and apply an educational program to improve self-efficacy and nursing job satisfaction and reduce working bullying, which are influencing factors of professional self-concept of intensive care unit nurse.