Abstract. Indonesia is a large country with different languages and cultures. That is why the obligation to master national language besides regional language and intercultural marriage are two of some reasons that Indonesian children have been being bilinguals since they were born. Therefore, this study aims to find the benefit to be bilinguals and what kind of challenges do they have to face. This is a library research that the data were collected by analysing journals and books. The result of this study showed that bilingual children experience some benefits compared to monolinguals, such as understanding two separate language systems and grammar principles, having better working memory and executive functioning, and mastering more receptive vocabulary. Meanwhile, the challenges they need to face are that they have to deal with code switching.