The language Acquisition in early childhood is a golden period that determines the development of children's psychology. Many parents do not know the language acquisition barriers that might occur to their children, so that language acquisition barriers are not addressed early on. Therefore, the researcher is interested in conducting research on language acquisition in children aged 36 months. This study aims to determine language acquisition in the field of phonology and the Mean Length of Utterance in children. This research employed a descriptive method with qualitative analysis techniques. The subject in this study was a female child aged 36 months. Data collection is done by documentation technique. The results showed that the acquisition of phonological level language in the subject of the study still occurred on fluency or pronunciation errors in the form of phoneme replacement and phoneme obsession at the beginning and end of syllables. The obstacles in language acquisition were mostly caused by environment and family. The Mean Length of Utterance is 2.75, which is at level 6, one level lower than children in her age.