The current research aimed to identify the effectiveness of a suggested unit in science based on social-emotional learning (SEL) to develop an awareness of immunity and positive thinking for pupils of the Preparatory Stage, and in light of that, the research sample was selected from the second year of middle school. It consisted of (30) female students from the Kafr Saqr School Preparatory School for Girls for the academic year 2021/2022 AD, The research materials represented in the suggested unit in immunity, teacher’s guide and Student activity book were prepared. Research tools were prepared and applied to the research group, which consisted of (the cognitive test of awareness and behavioral test of awareness - the scale of attitude towards awareness and the scale of positive thinking) before, the suggested unit of the research sample was taught and after its completion, the research tools were applied remotely. The data was processed using the appropriate statistical methods. The results resulted in the presence of a statistically significant difference at the level (0.01) between the mean scores of the research group members in the pre and post application of the cognitive test for awareness as a whole and in its sub-dimensions each separately in favor of the post application, and there was a statistically significant difference at the level (0.01) between the mean scores of individuals The research group in the pre and post application of the behavioral test for awareness as a whole in favor of the post application, and there is a statistically significant difference at the level (0.01) between the mean scores of the research group members in the pre and post application of the scale of attitude towards awareness as a whole in favor of the post application, there is a statistically significant difference at the level (0.01) between the mean scores of the research group members in the pre and post application of the positive thinking test as a whole and in its sub-skills each separately in favor of the post application. Some recommendations and suggestions were presented in light of the results that were reached. Keywords: Social &Emotional Learning (SEL), Awareness of Immunity, Positive Thinking