Objective. To study trend of research work on at-home sexual education in Japan and analyze points to be solved. [Materials and Method] Japanese literature search on sexual education published during 5 years from 3/2001 to 3/2006 using key words “home”, “sexual education” and “puberty” from major medical journals and data-base of J-dream and Cinii. Results: 33 publications were abstracted (21 original articles and 12 others). Those are all research work and, in many studies, questionnaires distributed to parents after lecture meetings or through students were analyzed. The researchers were doctors, university academics, midwives, etc. The result showed that parents’ sexual knowledge is too little to educate children at home. Many reports also pointed out that parents have negative images on sex and a resistance to talking about sex realizing the necessity of sexual education. Many researchers pointed out that, for successful at-home sexual education, it is necessary to change the parents’ perception on sex and intervene in sexual education for males. [Conclusion] Continuous support to parents, father in particular, is necessary so that they can tell children about sex, based on scientific knowledge, with appropriate words timely according to child’s developmental stage. Development of an educational program for parents is also necessary to facilitate research and improvement of these points.