The Impact of Underage Marriage on Household Welfare (Case Study in Desa Trangkil kecamatan Trangkil)". Early marriage is a marriage carried out by someone who is a teenager or under the age that has been determined by UU No. 16 of 2019 concerning Amendments to Law No. 1 of 1974 concerning marriage, which explains about the age of a person who can marry, namely men and women who are already 19 years old. The purpose of this study was to find out about early marriage, the factors that cause early marriage, and the impact of early marriage in Trangkil Village, Trangkil Regency Pati.To find out the problem comprehensively and more deeply, in this study a qualitative field approach or field research is used that highlights certain social situations by describing reality correctly, formed from words based on relevant data analysis techniques obtained from natural situations. useful for making provide data and facts regarding the impact of underage marriage on household welfare in Trangkil Village, Trangkil District. Then the data were analyzed systematically so as to obtain in-depth answers. From the results of this study, it was found that the factors that caused early marriage were different from before. The main factors behind early marriage in Trangkil Village, Trangkil District, are pregnancy factors outside of marriage, educational factors, and economic factors. Based on the analysis of existing data and facts, it can be concluded that early marriage has positive and negative impacts. The positive impacts include avoiding free sex, easing the burden on parents, marrying young to prevent having small children when they are old. While the negative impacts are divorce, poverty, physical and mental health disorders. Different people's views on early marriage are positive and negative depending on the impact and factors behind early marriage.