Developing countries face a shortage of nurses with higher education, such as those with a master’s degree. However, few studies have investigated the interaction between career decision and professional commitment (PC) of nursing students, especially for postgraduates. This study performed correlation analysis for career decision-making self-efficacy (CDMSE) and PC of 545 nursing postgraduate students from nursing schools at 19 universities or colleges throughout mainland China, who came from different regions, and possessed different years of study and different types of degrees as well as part-time job experiences. Data reliability and validity were confirmed for both Career Decision-Making Self-Efficacy Scale for university students (CDMSE-R) and Professional Commitment Questionnaire (PCQ). We found positive correlations between factors of PC and CDMSE. The score of CDMSE was different between regions, degree types, grades, and part-time job experiences. According to our results, we suggest nursing education or career advisory services should promote the PC of nursing students according to factors of their CDMSE scores.