It seems that there has been a low sense of guilt for tax evasion in Korea. It is partly because Korean tax evasion laws have not been construed and enforced efficiently enough to be justified in terms of criminological theories as well as criminal policies. Therefore, this article deals with how to improve Korean tax evasion laws especially based on comparative analysis with tax evasion laws in the United States. The elements of criminal tax evasion in Korea are highly similar to those in the United States. Nevertheless, there are several differences between two countries in construing and applying these elements. Of course, some of these differences result from the fact that Korea and the United States have different legal systems and cultures. However, the rest of the differences could shed light on how to improve each country`s tax evasion laws. The U. S. tax evasion laws could provide the Korean tax evasion laws with the following two improvement points. First, proof of unreported or unpaid tax is much more important in Korea than in the United States. Nevertheless, while the U. S. tax evasion laws have made efforts to enhance the accuracy of the amounts of unreported or unpaid tax when allowing indirect methods of proof to be used, the Korean tax evasion laws have not sufficiently done so. Therefore, the tax evasion laws in Korea need to promote the accuracy in determining the amounts of unreported or unpaid tax. Second, the U. S. tax evasion laws have allowed a defendant in a tax evasion case to defend his or her case on the basis of ignorance of law or mistake of law. In other words, ignorance or mistake of law has negated willfulness, which is the mens rea element of criminal tax evasion in the United States. Like the U. S. tax evasion laws, it would be desirable for the Korean tax evasion laws to apply Section 16 of the Korean Criminal Act and thereby make a tax evasion defendant nonresponsible for tax evasion when there was a mistake of law on the defendant`s part, and there were reasonable grounds for such a mistake.