The parent’s knowledge became one of the important factors in understanding the changes which occur during periods of teenagers reproductive function that can prepare teenagers well in dealing with it. The purpose of this research is to know the relation between parents knowledge about reproduction health and parents behavior to give information about reproduction health to teenagers. This research is done with the cross-sectional design, using the parents which stay with their children, especially teenagers, as much as 59 respondents, in Tamantrto, Kasihan, Bantul, Yogyakarta. The result of this research use Chi Square and get p value 0,000 and OR 10.000. Increase the parent’s knowledge is very important because can give an information about the health of reproduction well being to teenagers.