Nowadays, the automatic contract renewal is widely applied. However, there is no explicit mention of the manner of automatic contract renewal. Sometimes the contract such that it occurs without the consent of the consumer or the consumer cannot perceive and understand the contents of the contract, leading to the benefit loss of consumers. The purpose of this thesis is to study the legal problems of the automatic contract renewal in the Thai legal system. The studies focused on trading of goods and services transactions, which are renewed automatically in the contracts between entrepreneurs and consumers in accordance to the Civil and Commercial Code, the Unfair Contract Act B.E. 2540, and the Consumer Protection Act B.E. 2522. The study of transactions that are identified by specific laws, is not conducted in detail. In addition to the provisions of Foreign law, the thesis take into account the provisions of automatic contract renewal in the European Union law pursuant to Council Directive 93/13/EEC of 5 April 1993 and Directive 2011/83/EU of 25 October 2011, which is intended to prevent unfair terms from continuing to be used in contracts, such as automatically renewing a contract of fixed duration when the deadline fixed for the consumer to express this desire not to renew the contract is unreasonably early. These provisions are similar to the German’s law. According to the Civil Code of the Federal Republic of Germany 2002, Book 2 Law of Obligations, Division 2 Drafting contractual obligations by means of standard business terms, it provides more details of the duration of continuing obligations than the law of the European Union. For the studies of the automatic renewal terms in the United States of America, the Uniform Commercial Code, the study focused on the definitions. Then, the study of the Illinois Automatic Contract Renewal Act 2000 amended in 2005 has been examined. Meanwhile, the California Business and Profession Code amended in 2010 had been investigated. The provisions describe the detail of automatic renewal terms and protect consumers from the automatically renewal such as the consumer's consent to renew the contract automatically, disclosure of the automatic renewal clause clearly and conspicuously in the contract, and notification to the consumer, etc. According to the studies, the thesis found that there is no explicit mention of the manner of automatic contract renewal in Thailand. And now, the provisions of Thai law are not enough to protect the parties who do not voluntarily renew the contract automatically. The author proposes to use the interpretations to assist in the consideration of the legal problems of the automatic contract renewal such as the interpretation of the parties’ intentions. Moreover, for the purpose of protecting the consumer, the author proposes that requiring entrepreneurs need to obtain consent from consumers before the contract automatically renewed and need to disclose the automatic renewal clause clearly and conspicuously in the contract and must be notified in writing term to the consumer before it is automatically renewed, so that consumers who do not voluntarily renew their contracts are protected