Psycholinguistics in language learning and teaching has a role as a science that studies human language behavior that is universal so that someone will be able to learn and master any language presented to him. This study aims to explain the implementation of psycholinguistics in Indonesian learning and teaching elementary school. The research method used qualitative approach. This research is a descriptive research that is shown to explain and analyze the phenomenon of a state in the first grade students MI Ma'arif Watuagung District Tengaran Semarang regency In accordance with the above types of research, the researchers used an interactive model of Miles and Huberman to analyze the research data. Activities in qualitative data analysis performed interactively and runs continuously until complete, so that the data is already saturated. Findings of research results the implementation of psycholinguistics in Indonesian learning and teaching shows that there is a connection between Javanese (B1) and Indonesian (B2) which makes Indonesian language easy to learn by students. Indonesian and Javanese language equally cover the components of language and literacy skills which includes 4 aspects: listening (listening), speaking, reading, and writing. It is based on similarities in phonology, morphology, syntax, and vocabulary Javanese language (as the first language) that resembles a second language (as Indonesian). A lot of Javanese uptake words in Indonesian. Implications in the use of everyday language, students more often use the Javanese language than the Indonesian language. Javanese language serves as a source to meet both formal (in the classroom), informal and nonformal communication needs.