The tourism ministry noted that the growth of domestic tourist in Indonesia since 2014 has decreased drastically to -1.57%. Tourism industry is one of the leading sectors to increase state revenues. Foreign exchange income from tourism occupies the fourth position after oil and gas, coal mining and palm oil industry. This research aims to examine the phenomenon of information sharing that occurs
in groups in social media especially senior high school students. Students are the domestic tourists with the largest percentage in Indonesia. This research also
examines how communication plays a role in sharing information in groups as well as in self-relevant values. This research has two research questions: 1) Does
transactive memory system affect relationship between formal and informal communication with self-relevant value which occurs in social media? 2) Does transactive memory system affect self-relevant value, which occurs in social
media? This present research is aiming to investigate the information sharing in senior high school students' point of view. This research also analyzes the relationship between formal and informal communication, transactive memory systems, and self-relevant value. In order to meet the aims of this research, quantitative study especially survey study has been conducted. The data was taken from students in SMAN 18 Bandung. Because of the total Indonesian domestic tourists who are senior high school students, West Java has the highest percentage. The total sample data is 807 in the form of questionnaires. The data is analyzed using statistics method; Confirmatory Factor Analysis (CFA) and Structural Equation Modeling (SEM). Proposed model tested using AMOS 21. The fit indices of the proposed model show good fit. In this research there are 5 hypotheses and accepted all. Found that 1) formal and 2) informal communications positively affect transactive memory systems, 3) transactive memory system has a positive effect on self-relevant value, transactive memory systems became a good mediator between 4) formal and 5) informal communication with self-relevant value. The finding results also suggest some managerial implications.