Other-regarding preferences (such as trust, reciprocity and altruism) between companies, between consumers and retailers, and between employers and employees are integral elements in determining economic performance. Social trust which is a core element of social capital, especially, is known to reduce transaction costs, help solve collective action problems, and contribute to economic, social, and political development. Therefore, social trust has been given a great deal of attention across an array of academic disciplines for its role in promoting cooperation among individuals and groups, and for its positive influence on economic performance. Most studies describe Korea as a low-trust society than Japan or China. To identify the causes of social trust, this paper focuses on differences of social values (perception on competition and wealth accumulation) in 4 countries (Japan, China, Korea, and United States). Based on World Values Survey data, this paper analyzes effects of the social values on social trust. Social trust was measured by degree to which a respondent thinks that most people can be trusted. Perception on competition was measured by the degree to which a respondent thinks that competition is harmful, and perception on wealth accumulation was done by the degree to which a respondent thinks that wealth can grow so there is enough for everyone. The results showed that social trust was affected by perception on competition and wealth accumulation. A respondent showed higher level of social trust when he (or she) perceived positively competition and wealth accumulation. For enhancing social trust in a country, it is not easy to reduce income inequality and corruption which were reported as causes of social trust by previous studies. Compared to them, social values can be changed more easily by various concrete measures like education and mass-media. Differently from previous studies this paper stresses the concrete measures to enhance social trust in a country.