This research aims to design a clinical interview in mother tonque that can be used for decreasing elementary school students' misconceptions especially about simple electrical circuit. Participants were 9 grade-6 students who speak Thionghua “Khek” as their mother tongue. They are respectively divided into three levels of knowledge such as high, medium, and low. Each of the level of knowledge consists of three students that have been chosen by purposive random sampling. Students' conceptual understanding and misconceptions were prompted by a set of diagnostic test with three alternative answers and followed a clinical interview about simple electrical circuit to remediate their misconceptions. There is no significant difference of conceptual change between student with high, medium, and low level of knowledge. Usage of a mother tongue in the posttest is better than in Bahasa for the students' conceptual change. This design of clinical interview in mother tongue can be used to foster conceptual understanding and to decrease most of the students' misconceptions in simple electrical circuit
