This study has developed the sex education contents including new natural family plan, concept and principle by receiving the opinions and advices from professionals and professors on sex education, by amending and supplementing existing teaching materials on sex, and examining the books related with sex education contents that reflect the request of teachers and students, and the lack of sex education teaching materials which have been the reason that needs of school sex education has been highly recognized but not vitalized. The developed sex education contents are 8 areas such as knowing my body right, caring my body, observing the ability of being pregnant, marriage, sexual intercourse, process of pregnancy, miscarriage, and sexual violence, 30 lower areas, and 105 detailed contents in their composition, and here are the results of analyses of the degree of request of nurse teachers and the students on them. The teachers showed highest request in the area of sexual violence(M =4.67), the next was my body care(M=4.44), knowing my body right(M =4.38), process of pregnancy(M=4.13), marriage(M=4.11) and sexual intercoursen (M=3.98), ways of judging the ability of being pregnant(M=3.88), and miscarriage(M=3.72) showed comparative higher request than normal. Not like the teachers, the students showed that they requested Marriage area as the highest need(M=3.04) and next was sexual violence(M=3.02), caring my body(M=3.00) to have been higher than normal. Process of pregnancy(M=2.99), Sexual intercourse(M=2.81), miscarriage(M = 2.77), observation of the ability of being pregnant(M=2.74), and knowing my body right(M=2.70) have been the requests lower than normal. This study showed that sexual violence, marriage, caring my body, were the items most requested by both the leacgers and students and in elementary school the development of sex education teaching materials on natural family plan suitable to the level of development of the children has been requested as it has had no inclusion of the concept of natural family plan, and the students in elementary school are concerned on indirect sexual contents related with physical health like regular exercise rather than direct sexual education contents including sexual intercourse. All these show that they are still so naive on sex. The sense of the teachers on sex has been connected with the level of achievement of sex education of the children as it has been the important cause of deciding the contents of sex education. Therefore the materials developed onesidedly by leaders without reflecting the needs or the preference of the students might be worries of bringing shameful. low quality and negative opinions on sex, and on the other hand the children might lose the concerns and interest on sex education, So the materials should be developed to have the contents of sex education coinciding with the request of the children.