<![CDATA[This research is motivated by the increasing intensity of social media use among elementary school students, which is thought to be related to their mastery of Indonesian vocabulary. Social media is one source of language exposure that can influence students' vocabulary development. This study aims to determine the relationship between the intensity of social media use and the mastery of Indonesian vocabulary among fourth-grade elementary school students in Pesisir Selatan Regency. This study uses a quantitative approach with a correlational method. The study population was 35 fourth-grade students from three elementary schools in Pesisir Selatan Regency. The sampling technique used total sampling so that the entire population was used as the research sample. Data on the intensity of social media use were collected through a Likert scale questionnaire, while data on Indonesian vocabulary mastery were obtained through a multiple-choice test. Data analysis was carried out using descriptive statistics, analysis prerequisite tests including normality and linearity tests, and hypothesis testing using Pearson correlation with the help of the SPSS program. The results showed that the intensity of students' social media use was in the moderate category with an average value of 2.84, while their mastery of Indonesian vocabulary was in the high category with an average value of 14.14. The results of the hypothesis test showed a significance value of 0.043 (<0.05) with a Pearson correlation coefficient of 0.344. Thus, there is a positive and significant relationship between the intensity of social media use and the mastery of Indonesian vocabulary of fourth-grade elementary school students in Pesisir Selatan Regency, but the level of relationship obtained is in the low category.]]>
