This study aims to analyze the students’ mastery of concepts on the topic of energy during the distance learning when Covid-19 pandemic. The method used in this study is descriptive quantitative. The sampling technique used purposive sampling, where the determination of the study sample is based on gender. The sample in this study is 116 people. Students’ mastery of concepts refers to Bloom’s Taxonomy, namely C1 to C4. The instrument used was a cognitive ability test with 22 multiple choice questions. Data were analyzed using scoring techniques with the Guttman scale. The scores obtained are made into percentages and the results are grouped by category. The results showed that during the distance learning process, the students’ mastery of concepts was in the “enough” category with a percentage of 54%. Based on each aspect, the mastery of the concept in the C1 aspect shows an achievement of 81% with the “very well” category, 49% for the C2 aspect in the “enough” category, 57% for the C3 aspect in the “enough” category and 48% for the C4 aspect with the “enough” category. From the results of the study, efforts are needed to improve students’ mastery of concepts through appropriate learning strategies.