Abstract: Objective:To investigate the organizational identification and voluntary behavior of nurses in a tertiary hospital,and its relationship.Methods:Two hundred and forty-two nurses from tertiary hospital were investigated using "organizational identification scale" and "voluntary behavior questionnaire" according to the convenience cluster sampling method.Results:The participators included 88 nurses(36.4%) attending various volunteer activities and 154 nurses(63.6%) never taking part in volunteer activities.The scores of organizational identification and voluntary behavior were(31.83±5.27) and (2.20±1.09),respectively.The score of organizational identification in nursing managers was significantly higher than that in nurses(P<0.01),the score of organizational identification in more than or equal to 36 years old nurses was significantly higher than that in 26 to 35 years old nurses(P<0.01),the score of organizational identification in nurses with working time for 6 to 10 years was the lowest,and the score of organizational identification in nurse-in-charge and above title nurse was more than that in senior nurse(P<0.05).The score of voluntary behavior in nursing managers was significantly higher than that in nurses(P<0.01).The organizational identification of nurses was significantly positive correlation with voluntary behavior(r=0.230,P<0.01).Conclusions:The organizational identification of nurses from tertiary hospital is positive,and the voluntary behavior is not optimistic.Organizational identification plays a role on predicting the voluntary behavior.Nursing managers should strive to further improve the organizational identification of nurse,and encourage nurse to participate in the volunteer service activities.