Abstract: Jones (1991) postulated ‘moral intensity’ of the issue as a starting point in the ethical decision making process. He argued that ethical decision making is issue contingent, and the characteristics of the moral issue itself affect ethical decision making of a moral agent. Jones identifies six categories of moral intensity: 1) magnitude of consequences, 2) probability of effect, 3) temporal immediacy, 4) concentration of effect, 5) proximity, 6) social consensus. The former study mainly explored the relationship between moral intensity and ethical decision making, but ignored investigating the influencing mechanism. The present study tried to include empathy into the Issue-Contingent Model to explore the mechanism of the influencing of moral intensity on ethical decision making in the business. The present paper reported the results of a vignette- and questionnaire-based research project. One scenario about the employee’s health was created allowing independent manipulation of the four MI components (magnitude of consequences, probability of effect, social consensus, proximity) as high or low moral intensity. All possible combinations were utilized, resulting in 16 different versions. The participants were presented with one version of the scenario. The scenario was followed by items assessing ethical perception, ethical judgment and ethical intention, empathic response, perceived moral intensity, dispositional empathy (including empathic concern and perspective-taking). All items were on 7-point anchored scales. The study selected 256 MBA students as participants. The LISREL8.51 was used to make the structural equation model of the role of empathy in the influencing of moral intensity on ethical decision making in the business. The results indicated that, 1) the empathic response completely mediated the relation between moral intensity and moral recognition, and partly mediated the relation between moral intensity and moral judgment, moral intent; 2) Dispositional empathic concern could influence ethical perception, ethical judgment and ethical intention through perceived moral intensity and empathic response; 3) Magnitude of consequence, social consensus, and probability of effect affected moral judgment and moral intent by different mechanism. Magnitude of consequence could not only influenced moral judgment and moral intent directly but also through the empathic response. Social consensus mainly had the direct influence on moral judgment and moral intent. Probability of effect influenced moral judgment and moral intent mainly through the empathic response. Those findings deepen our understanding of the influencing mechanism of moral intensity on ethical decision making, especially the role of emotions and reasons in ethical decision making. The future study is needed to extend the findings to the more ethical scenario in the business, such as some decisions which do goods for other people. In addition, the present study found that empathy had important role in the effect of moral intensity on ethical decision making, and the future researches can also manipulate the level of empathy response to explore whether the level of empathy can moderated the effect of moral intensity on ethical decision making.