This paper posits one of Judicial Review Standards that have played an important role in the U. S Constitutional adjudication since1960s. Less Restrictive Alternative Test means that a law or government regulation, even when based on a legitimate government interests, should be crafted in a way that will protest individual civil rights and liberties as much as possible, and should be only as restrictive as is necessary to accomplish a legitimate governmental purpose, and was placed there-given meaning - by the Warren Court ,yet another concept arising from the Court’appreciation of the fragility of free speech rights, and the importance of protecting them against indirect, as well as direct, assault(Shelton v. Tucker, 364 U. S. 479 ). Less Restrictive Alternative Test is one of the criterias for judging of constitutionality in the U. S Constitutional Litigation. This test has many controversial issues, for instance, scope, patterns, interest balancing, duty of elucidation, utility, burden of proof.This paper is composed of three parts. PartⅠ of this paper describes the purpose, scope and the method of the study, and surveys the concept and significance of LRA Test in the U. S Constitution : popularly called as "proportionality principles" in Korea. PartⅡ discusses the issues of application of LRA Test that has many critical questions. Finally, Part Ⅲ concludes that LRA Test has operated U. S Consitutional Litigation.