Objective To explore the deep reason for the lack of reproductive knowledge among migrant youth. Methods Qualitative research method was used with in-depth interview as the major approach to collect data. Results The results showed that lack of formal sexual education and the special social status were deep reason for their knowledge lack. Very few of them had received sex education in school. Before falling in love and beginning to date,most girls and some boys have no interest in sexual related knowledge. The knowledge they have usually come first from peer communication and are full of mistakes. As growing up,mass media,like TV and magazines begin to be their major knowledge sources. But many get the information from TV dramas,novels or advertisements,and few from formal educational programs. Working long hours each day,with little leisure time and living isolated in cities,migrant people rarely benefit from the ongoing education activities in cities. Conclusion Special sexual and reproductive health education program are needed urgently among unmarried migrant youth,particularly female. Objective To explore the deep reason for the lack of reproductive knowledge among migrant youth. Methods Qualitative research method was used with in-depth interview as the major approach to collect data. Results The results showed that lack of formal sexual education and the special social status Very few of them had received sex education in school. Before falling in love and beginning to date, most girls and some boys have no interest in sexual related knowledge. The knowledge they have usually come first from peer As growing up, mass media, like TV and magazines begin to be their major knowledge sources. But many get the information from TV dramas, novels or advertisements, and few from formal educational programs. Working long hours each day, with little leisure time and living isolated in cities, migrant people rarely benefit from the ongoing education activities in cities. Conclusion Special sexual and r eproductive health education program are needed urgently among unmarried migrant youth, particularly female.