Nowadays, the explosive evolvement of Internet. which is referred to as EC, has been prevailing. That has given the chance all of the world consumers to contact all of the world companies to enter into business relationship. But, electronic commerce laws have been established per conventional jurisdiction. some legal issues take place in the field of cross-border electronic commerce, including the governing law and competent courts. In this situations, it is gradually and widely required to lay down the internationally harmonized electronic commerce legal framework. Now, there are a lot of legal issues assumed in EC, in this study, we studied three precedence problems concerning B2C: Consumer Protection Law regarding B2C, Personal Information Protection Law in Private Sector regarding B2C, Web Site Trust Mark System.