The relationship study of the hospital organization culture, leadership,and organizational citizenship behaviors. Abstract This research is aimed at hospital organization culture, leadership, organizational citizenship behaviors of medical organizations. The sample of this research focuses on 10 local teaching medical centers in southern Taiwan, which includes 51 departments and superiors, and the number of polled employees reaches 273.This has resulted in: ¡]1¡^Leadership and organizational citizenship behaviors have positively correlation; contingent reward is most correlated with courtesy.¡]2¡^Organizational culture and organizational citizenship behaviors have positively correlation; social responsibility is most correlated with civic virtue.¡]3¡^Organizational culture and leadership have positively correlation; scientific truth seeking is most correlated with providing an appropriate model.¡]4¡^ Leadership positively associates with organizational citizenship behaviors; identifying and articulating a vision is the most associated with conscientiousness.¡]5¡^ Organizational culture positively associates with organizational citizenship behaviors; in this item, civic virtue is most affected¡]6¡^ Organizational culture positively associates with leadership; scientific truth seeking is the major factor to providing an appropriate model. As to the influence of the interaction of leadership and organizational culture to organizational citizenship behaviors, the result is as the following: ¡]1¡^in the condition of emphasizing on social responsibility culture, providing individualized support positively associates with courtesy base on low social responsibility while the 2 factors are not obviously related to each other base on high social responsibility; providing individualized support positively associates with altruism base on low social responsibility while these two factors are negatively associative to each other base on high social responsibility ¡]2¡^in the condition of emphasizing on strengthening relations culture, providing individualized support positively associates with altruism base on weak relations while the 2 factors are negatively associates to each other base on high strong relations ¡]3¡^in the condition of emphasizing on customer orientation culture, providing individualized support positively associates with civic virtue base on weak customer orientation while the 2 factors are negatively associates to each other base on strong customer orientation ¡]4¡^ in the condition of emphasizing on scientific truth seeking, high performance expectations positively associates with civic virtue, however, high performance expectations influences civic virtue more in strong scientific truth seeking than in weak scientific truth seeking ¡]5¡^ in the condition of emphasizing on integrity and trust culture, high performance expectations positively associates with altruism, however, high performance expectations influences altruism more in strong integrity and trust culture than in weak integrity and trust culture. Furthermore, providing individualized support positively associates with altruism; in comparison with strong integrity and trust culture, the influence between these two factors is more in weak integrity and trust culture.