This study explores teachers perceptions on the effectiveness of elementary science online courses and identifies areas for improvement. For this study, 100 teachers who had previously taught elementary science online courses were asked to complete a questionnaire, which consisted of three components: general information on the participant, teacher s perception on the effectiveness of elementary science online remote class, and ways to improve elementary science online courses. The results were as follows. First, the elementary teachers thought that elementary science online courses improved students scientific thinking abilities, science process skills, scientific problem solving, scientific participation, and lifelong learning abilities, but they had a negative effect on their communication skills. Second, they thought that most science curriculum units that are easy to apply online courses were in the fields of earth science and biology. However, physics and chemistry appeared to be the most difficult fields regarding online courses. Third, they felt that content should be developed in order to improve students scientific skills, and a system for lending science exploration tools should be in place.