Background: The puberty of school children has many roblems with reproductive health. Knowledge of reproductive health is important for school children to be better prepared to cope with the change occurring. There is a big influence between information and reproductive health behaviors in school children. Issues related to the health of reproductive organs are itching in the genital and vaginal discharge of women. Research Objective: This study aims to determine the effect of peer education on the level of knowledge of school children about puberty and how to maintain reproductive organs in 2 Padokan Elementary School. Research Method: The tpe of research used quantitative research, pre-experimental research design with one group pretest-posttest design. The sampling technique using random sampling and the number of respondents were 72 students. This research using the Illustrative Questionnaire for Sexual and Reproductive Health Knowledge and P&G Always Changing Publish Education Program which has been adjusted to the norm and validity tested with correlation coefficient of biserial on 50 respondents with number r table is 0.361 and reability using KR-20 with the result is 0.959. Result: This study uses Wilcoxon test to know the influence of peer education on the level of knowledge of school children abot puberty and how to maintain reproductive organ health in SD 2 Padokan. The result is 0.438 with p is 0.05 so it can be concluded that there is no influence of peer education on the level of knowledge of school children abot puberty and how to maintain reproductive organ health in SD 2 Padokan. Conclusion: There is no influence of peer education on the level of knowledge of school children about puberty and how to maintain reproductive organs health in SD 2 Padokan .