This development research aims to produce teaching material products in the form of modules assisted by advanced organizer learning models that are valid, practical and effective to improve students' mastery of concepts on temperature and heat material. The research design used is the 4D model which consists of define, design, develop and disseminate. Products developed in the form of a Learning Implementation Plan (RPP), Assisted Teaching Module with the Advance Organizer model, and test instruments in the form of concept mastery questions. Data collection techniques used validation sheets, questions and student response questionnaires. The validity data were analyzed by using expert validation analysis to determine the validity value of the device. The increase in mastery of physics concepts was analyzed by determining the standard gain from the results before and after learning. The validity of the Learning Implementation Plan (RPP) was 84.72%, the Assisted Teaching Module with the Advance Organizer model was 82,07% and the conceptual mastery questions were 76,85%. The reliability of RPP, teaching modules and concept mastery test questions were above 75% which showed that all aspects assessed were included in the reliable category. Modules are also effective for improving mastery of physics concepts. Obtained N-gain of 0,43 in the medium category. Based on these results it can be concluded that the teaching materials developed are valid, practical and effective to be used to improve students' mastery of concepts