The development of technology has brought us shifting from offline toonline transactions. On the other hand, there are some major issues regarding the development of online transactions which is legal protection for consumer. Online transactions were built based on trust between the seller and the consumer. Hence, in order to run an online business, we have to make sure that moral rights and obligations are needed, namely business ethics. The main problem of this research is how the law protect consumers who are disadvantaged in online transactions (E- Commerce) and how business ethics works in online transactions (E-Commerce). The method used is normative legal research using secondary data mainly because this research uses library research. The results of the study found that there were cases of violations of consumer rights and violations of business ethics by business owners, consumers and marketplaces in online transactions. So,it can be concluded from this research that consumers who are disadvantaged in online transactions should be protected by law as in the Consumer Protection Act.Although the Consumers Protection Act has regulated that business owners that violate the provisions will get sanctions, there are only business owners who do notpay attention to what is obligations, prohibitions, and responsibilities for business owners. Business ethics in buying and selling apply to any kind of transaction whether it is offline or online. Business ethics has an important role in building consumer trust and the ongoing business activities themselves. However, at this time there are still business owners, consumers, and marketplaces who do not apply business ethics which is the basis business.