Abstrak The aims of this study are to improve the mastery of science concept and the ability to design science learning of preservice teachers through blended learning in elementary science education course. This study involved 39 preservice teachers taking Elementary Science Education course at the University Education of Indonesia at Purwakarta. The method used are pre-experimental design with one group pretest-posttest. This research used test related with Plant Physiology and Anatomy and also Earth and Space topic to examine the mastery of science concept. In addition, rubric was used to evaluate the lesson design. The results showed that there are significant differences between the mastery of concepts and the ability of the students in designing science lesson plans before and after the implementation of the elementary science education lecture-based blended learning.