Altruistic behaviors are voluntary acts intended to bene?t or help others, which can be predicted by many psychological traits. The most prominent ones are egocentrism, an individual’s propensity to be privy to one’s own but not to others, and empathy, a set of constructs which all concern responsivity to others but are also clearly discriminable from each other. These two variables, however, have opposing effects on altruism. Egocentrism tends to decrease altruistic behaviors/tendency, while empathy tends to increase it. It is not entirely clear as to how these two traits interactively influence altruistic behaviors/tendency. Two studies were carried out to examine the moderating effect that trait (Study 1) and state (Study 2) empathy exerted on the relationship between egocentrism and altruistic tendency (Study 1)/behavior (Study 2) in female university students. In Study 1, a questionnaire survey was conducted exploring the relationships among trait empathy, egocentrism, and the tendency to perform altruistic behavior. 336 female college students filled out a battery of questionnaires, including the Interpersonal Reactivity Index (IRI, as a measure of trait empathy), the Egocentrism Scale, the Altruistic Behavior Scale of Philosophies of Human Nature (as a measure of altruistic tendency) and a Social Desirability Scale. A multiple regression was carried out with egocentrism as independent variable, altruistic tendency as dependent variable, and trait empathy as moderator . The results showed that trait empathy moderated the relationship between altruistic tendency and egocentrism when social desirability was controlled. Specifically, for participants with high level of trait empathy, their egocentrism scores negatively correlated with altruistic tendency; no significant relationship was found between egocentrism and altruistic tendency for participants with low level of trait empathy. In Study 2, we primed the participants into either high or low state empathy and examined whether this experimental manipulation of empathy could influence the relationship between egocentrism and actual altruistic behaviors. 48 participants were randomly assigned into two equal-sized groups according to their egocentrism scores in Study 1. Participants received 30 RMB rewards immediately when then come into the lab. Then they were left alone for the rest of the experiment using computerized program. Participants first completed an irrelevant attention task to cover the main purpose of the study. Then the expiriment group read a story which could prime state empathy based on a pilot study, while the control group read a control article about the same length. After that, participants was informed that the Psychology Department was fundraising for a welfare institution. They could voluntarily donate some of the rewards to the donation box, the amount of which was used as a measure of altruistic behavior. Primed empathy significantly invoked altruistic behaviors. The significant interaction between state-empathy and egocentrism indicated that primed state empathy provoked more donations on participants with lower level of egocentrism than those with higher level, while in the control group the amount of donations did not differ between participants with different levels of egocentrism.