Happiness become a hot topic in recent years in the area of psychology. Scholars try to use experimental results in psychology to boost the human happy experiences, guide folks’ life, and influence public policy. But recent research mainly focused on the descriptive and psychological aspect of the conception of happiness, and neglected the normative and evaluative aspect. Virtue is the pre-requisite of happiness from both Confucian and Aristotelian tradition. Aristotle built his happiness theory on his view of virtue. In his theory, to reach the state of happiness, we need to behave in a virtuous way. Confucian tradition also hold a belief that, pure happiness consistent with self-control state which toward ethical norms. Experimental results showed that, behave virtuous can boost happiness. First, religious people were found happier than nonreligious people. This was an indirect evidence because religion always push people to behave in a virtuous way. Religious people were more likely to experience positive emotion, were less inclined to feel anxiety and depression. That might because religious people got more social support, had higher self-esteem and found more meanings in life. Second, people behave more virtuous, they feel happier. This is the direct evidences. People who donated money or spent his own money on others was found happier that who spent money on himself. Prosocial spending make effectively good influence on human emotion and meaning system. This might be an evolved psychological mechanism that we are born to be good. In other research, young kids were happier giving treats away than they were when receiving the same treats themselves. Volunteers also happier than control group in other studies. Writing also can boost human happiness, wrote down his own moral behavior several times per week, the author will be happier. These behavioral effect also found on children participants. Whether doing a moral behavior could improve happiness or not is still an ontology question. Another important question is about the epistemology. That is, how we judge a person who obtain virtues, he is happy or not when compare to other persons who do not obtain virtues. Experimental results showed that, people tend to judge good people happier than bad people. In one condition, behavioral agents was described as a Red Cross field doctor who had both positive and negative mental states. In the other condition, behavioral agent was described as a Nazi death camp doctor who experienced the exact same type of mental states. Comparing the two conditions, participants were significantly more likely to agree with the statement that Richard is happy when he was described as a Red Cross doctor than when he was described as a Nazi doctor. Moreover, when researchers showed a more ambiguous moral situation, like a gay man who, though conflicted because of a religious upbringing, began dating another man, the results were more interesting. When looking at how judgments of immorality and distress predicted judgments of happiness, the judgments of immorality predicted judgments of happiness in a way that was independent of perceived distress. Both judgments of distress and judgments of immorality influenced attributions of happiness, the impact of normative judgments on judgments of happiness was not due to the difference in perceived distress. A series of studies testified this effect. In our belief, we tend to think virtue is the pre-requisite of happiness. Empirical research explained the relationship between virtue and happiness. But the problem of casual attribution of virtue on happiness, and the problem of instrumentality of virtue on happiness still need more research to give a satisfying answer. Because the attribution process is hard to identify in virtue and happiness, which one is the cause and which one is the result. Or if the causation process is a circle, we need more theories and studies to identify the complex mechanisms.