In designing the lesson teachers have to adapt the method or learning model with the material to be taught. In the teaching of measuring concept, students frequently faced with measuring instruments, micrometer, screw, scale, and so on. Direct Instruction Model would be suitable for teaching the measurement concepts specifically the skill of using measurement tools. The purpose of the study was to determine the level of students mastery on the concept of measurement through direct instructional model. Descriptive research with action in the class were used in this research to determine the level of students mastery on the measurement concept of the physical sciences in order to achieve competency. The samples were 25 seventh grade students on the second semester of academic year 2012/2013 of 11 Ambon State Junior High Schools. The instrument used was the test to measure the mastery of concepts. Performance test scores and daily tests are converted into the category of excellent, good, sufficient and poor. The results showed that the level of students mastery of the material is at very good and well with the percentage of the final results of formative student tests are 48.0% and 44.0% respectively. It can be concluded that the direct instructional model successfully improve student learning outcomes, especially to the concept of measurement.