Thrift shopping is an illegal in Indonesia. Thrift shopping violates several regulations, The prohibition on the import of used clothing is directly regulated in the Regulation of the Minister of Trade Number 18 of 2021 concerning Goods Prohibited from Exporting and Goods Prohibited from Importing. Article 2 paragraph (3) states that the Prohibited Imported Goods are in the form of used bags, used sacks, and used clothes. Attachment II to the Regulation of the Minister of Trade Number 18 of 2021 also lists used clothing as one of the goods prohibited from importing. In addition, in Law Number 7 of 2014 concerning Trade, Article 47 paragraph (1) states "imported goods must be in new condition". Even the Job Creation Law in its Article 46 stipulates that importers are prohibited from importing goods that are designated as prohibited goods to be imported, which in this case is used clothing. From an industrial point of view, these imported used clothes are considered very disturbing to the domestic market which is the market share for the small garment and convection industry which in the end, this illegal activity of importing used clothes has an impact on unfair business competition. Therefore, in this case the researcher wants to examine the impact of business competition with the buying and selling of imported used clothing on the garment industry in Indonesia, legal protection efforts based on Law Number 5 of 1999 concerning the Prohibition of Monopolistic Practices and Unfair Business Competition against Business Actors in Indonesia, and the policy in Indonesia which regulates the prohibition of the import of used clothing. To answer the problem, the researcher uses normative legal research. Researchers found that the presence of imports of used clothing will greatly disrupt the domestic market for the garment and convection industry. Such conditions will lead to a concentration of economic power by one or more business actors, which in this case are business actors importing used clothing, which results in the control of production and/or marketing of certain goods and or services so as to create unfair business competition and may harm the interests of the people.