Siri marriage is a marriage that is not recorded before the Registrar of Marriage but meets the pillars and conditions of marriage in Islamic law. Although Siri marriage is religiously valid because it meets the pillars and conditions outlined in Islamic law, in Indonesian legislation it has no legal force. The purpose of this study is: 1) To analyze and find the perception of society and the perpetrators of Siri marriage about Siri marriage. 2) To analyze and find the cause of Siri marriage in Muslim communities in Lombok. This type of research is a type of empirical legal research with a qualitative approach. To support this method, primary data sources are used through interviews, FGD, and observations as well as secondary data sources in the form of books and related literature. The results showed that: (1) In general, Siri marriage actors have the perception that Siri marriage is a legal form of marriage according to Islam, but it does not meet the requirements by country. The requirement is the recording by the Registrar of Marriage. (2) Siri marriage conducted by Sasak Lombok community is caused by: a) Being in Rantauan; b) Limited Knowledge about the importance of recording marriage; c) Practical reasons; d) Reasons for polygamy; e) Due to eloping; f) Not obtaining the permission of the first wife; g) Pregnant out of wedlock; h) Not getting parental consent; i). Reasons for religious law; j) Negligence on the part of the maid of marriage registrar in the village; k) Reasons for the absence of costs; l). Has not reached the specified age of law; m) Consider marriage registration important; n) Do not have divorce papers; o) Often divorced marriage; p) Reasons for employment, and q) Economic reasons. Based on the theory presented by Lawrence M. Friedman, non-compliance with the marriage law can be analyzed from three factors, namely the legal structure factor, legal substance factor, and legal culture factor.

Index Terms- Siri Marriage, Perception, Causes