Innovation in teaching materials used in online learning is very urgent based on students’ needs. This study aims to measure the effectiveness of contextual research-based teaching materials to improve students’ learning independence and concept mastery of acid-base solution properties. The research method is Research and Development, referring to Borg and Gall. The research subjects were 60 students and 7 science teachers who have used teaching materials based on contextual research findings. The data collection technique in this study is a test that aims to determine the concept mastery and a questionnaire to measure students’ learning independence. Based on the results of the study, it is known that the average percentage of student learning independence is 78% (Good category). Besides, an average value of 73.83 is obtained with an N-Gain of 64% (Medium category). The use of contextual research-based teaching materials can increase learning independence in terms of information search and concept mastery of acid-base solution properties. Keywords: Android-Based Teaching Materials; Learning Independence