The aims of this study were to determine the implementation inquiry-based blended learning on electrolyte and nonelectrolyte materials, student activities during learning, classical mastery, improvement of critical thinking, and student responses to learning. The research subjects were 34 students of class X IPA 3 SMAN 14 Surabaya of the 2021/2022 academic year. This research is a pre-experimental with One Group Pretest-Posttest Design. The results of this study were (1) The implementation of learning at the first meeting was 95,37% from the second meeting 94,73%, the implementation of the two meetings was in very good criteria. ( 2) The relevant activities of students at the first meeting were 90,12%, the second meeting was 93,83%, both of which were in very good criteria. ( 3) Classical completeness is 94,12%. ( 4) The critical thinking skills of students with indicators of analysis, inference, and explanation have increased as seen from the N-Gain scores of 0,92, 0,87, and 0,84, all of which are in the high category. ( 5) The response of students to inquiry-based blended learning is very satisfying with the percentage of positive answers as much as 90,12%. So, it can be said the implementation of inquiry-based blended learning is effective in improving critical thinking skills.