I tried to introduce the EPA in U.S. in this article. I already had researched “equal pay for equal value of work” in ILO, U.N., E.U., Japan, Korea, and the research had been published in Korea. So It is able to be said that this article is to perform the remaining task in light of comparative studies with respect to the “equal pay”. Conclusion are follows: First, though the principle of “the equal pay for equal value of work(called also ‘comparable worth’ in U.S.)” is now being recognized by the statutes in many countries, the Supreme Court in Gunther Case emphasized that it was not endorsing the principle. And then it was a very different point when I compared the EPA of U.S. with the statutes of E.U., Japan, Korea or the rules of ILO, U.N. Second, the pay discrimination based on sex is brought in the Court under both the EPA and the Title VII. There is, however, a gap between the EPA and the Title VII in its coverage each other. I suggested that their coverage needs to be equal to protect or overcome sex discrimination as soon as possible because the principle of the equal pay for equal work is a social justice established in our world. Third, the equal work involves jobs, in addition to the performance of which requires equal skill, equal effort, equal responsibility, performed under working conditions that are similar. Even though the comparable worth is not recognized by the Courts, the test of substantial equal works is found in many cases concerned by the federal Courts. Nevertheless, an employer's reliance on a free market system in which employees in male-dominated jobs are compensated at a higher rate than employees in dissimilar female-dominated jobs is not in and of itself a violation of the EPA and the Title Ⅶ. Fourth, under the EPA, in the pay difference cases, the employer avoids liability only by establishing that the pay difference was attributable to systems of seniority, merit, quality or quantity of work, or factor other than sex. A standard of the factor of the “other than sex” is important especially because this exception for the difference in pay between male and female is ambiguous itself, and so the exception is being argued well by employers in real. The Courts, however, have interpreted the exception narrowly. Finally, the Korea Labor Commission performs roles of resolution of labor disputes with respect to collective labor relations(unfair labor practice or adjustment of labor relation's dispute), a labor contract(transference or disciplinary, and dismissal etc.), a discrimination based on non-regular workers engaging in jobs dispatched or employed with fixed-period labor contract or part-time. In spite of its many roles, unlike the EEOC, the Commission does not has a right to sue theses disputes against the Courts under its authorization. And then, I suggested that, in cases of labor disputes above, under some requirements, a right to sue against the Courts by the Commission should be granted by amending the Labor Commission Act of Korea.