This study aims to improve the mastery of students' concepts in fifth grade students through the Brain Based Learning model. The location of the study was Sumberejo 04 State Elementary School, Ambulu Subdistrict, Jember Regency, with a research population of fifth grade students totaling 30 students. This study uses Classroom Action Research (PTK). The study was conducted in 2 cycles, by carrying out several stages, namely the planning, implementation and observation stages, as well as the reflection stage. Data collection techniques using tests in the form of written tests and non-tests in the form of observations, namely observation of teacher activities and student activities. The results showed an increase from cycle I to cycle II. For teacher activities in the first cycle, the percentage shows 75%, and in the second cycle increases to 92.85%. The activity of students in the first cycle is a percentage of 70%. And in cycle II, student activity increases, to 85%. While the increase in mastery of student concepts can be seen from the results of student evaluations from 75.91% in the first cycle to 88.95% in cycle II.