The purposes of this study were to understand the subjective nursing competence and affecting factors. The objects were clinical nurses in a medical center. 705 questionnaires were sent out, and 613 of them being effective. The retrieval rate was 87%. The questionnaire was based on a 5-point Liker scale, including six parts: care-giving, communicating, teaching, managing, research ability, self-growth and professional development. The results showed that the average of total nursing competence was 3.64 (±0.51). The part with the highest score was care-giving (3.97±0.49), and the lowest was research (2.88±0.75). Results from stepwise regression showed job satisfaction, age, the level of clinical ladder, and the amount of training could explain 27% of the variance in subjective nursing competence. The results of this research can provide references to evaluating the quality of nursing care, improving nursing education and nursing administration.