Purpose: The purpose of the research is to investigate the effect of self-image on work performance and controlling ability of self-leadership in relationship in between self-image and work performance. Methods: The data were collected from Mar 16th to April 15th 2009, a descriptive survey study was conducted with 140 nurses. Results: The hypothesis "Self image of nurse would affect on work performance" is supported ($R^2$=.335, p<.001). In the hypothesis of "Self-leadership would have controlling ability on self-image and work performance", as a result of regression analysis in independent variables of self-image(A) and self-leadership(B), adding relation of both variable($A{ imes}B$) would increase in 36.6% (p<.05). Conclusion: Self-image of nurse was confirmed that it had positive effect on work performance and that it had moderating ability on relationship between self-image and work performance. The shaping and strategic operation are required to increase self-leadership and positive development on self-image of nursed.