There are many assertions about the Paul's understanding of the Law. Catholic theologist Veronica Koperski categorized their assertions into five category. I studied the Paul's understanding of the Law in Galatians according to the function of the Law through this study. First, covenant obligation of Mount Sinai, Those who don't obey obligations are under curses of the Law. Second, enslaving power, Third, the expression of God's will. If we take these three functions of the Law into consideration, we can properly understand the apparently conflicting statements of Paul about the Law. We confirm the same results by the structure analysis about Galatians.