Bakomliggande faktorer och konsekvenser av den sneda könskvoten vid födseln och underskottet av flickor i Kina. Dynamics and Consequences of the Increasing Sex Ratio at Birth and the *Missing girls* in China (People's Republic of). A deeper understanding of the causes and consequences of the problem with ?missing girls? in China (People's Republic of). A preference of sons over daughters has always been a part of the Chinese culture. It has partly been manifested in a high so-called sex ratio at birth (SRB), i.e. the number of boys born per hundred girls. Under normal circumstances, there are approximately 105-107 boys born per 100 girls. Historical documents suggest that China (People's Republic of) has had high SRB for centuries and well into the mid 2000th century. By the beginning of the 1970s SRB in China (People's Republic of) was within the normal range, but after the introduction of the one-child-policy in 1979, it has risen steadily. Most alarming is the fact that the SRB has recently continued to increase in some areas and, at the same time, have spread to new geographic areas and social groups, previously unaffected. The latest available statistics show that in 2005, the SRB was 120.5 national wide. According to the 2000 census, the estimated number of China (People's Republic of)?s missing girls was 40.9 million. Son preference? has been considered particularly strong in rural areas and among less educated parents and it has been implied that the current high sex ratios may be a transitory phenomenon that will diminish with modernization. Contrary to these expectations, the SRB is now rising even in urban areas, among well-educated couples. The rising sex ratio, in the context of the rapid demographic transition with falling fertility, is considered as one of the most alarming demographic and social issues in China (People's Republic of) today. The issue of the ?missing girls? in China (People's Republic of) has aroused broad attention from scholars, the public, Chinese central and provincial governments, and the international community. Most studies, though, have focused on regional trends trends and differences, but very little research has been conducted on a deeper understanding of the causes and consequences of the increasing SRBs. The project ?Dynamics and Consequences of Sex Ratio at Birth in China (People's Republic of)? is mainly a qualitative study, with in-depth interviews with young couples in one rural and one urban area in Northern China (People's Republic of). An additional study includes interviews with village level officials. The project focuses on the on cultural, religious and socio-economic factors that have stimulated and intensified son preference, for example the lack of a social-security system, especially in rural areas, decision-making within the family, and the strict patrilineal and patrilocal family system in China (People's Republic of), which put the responsibilities upon male descendants for economic, socio-cultural and religious functions, all of which encourage son preference. This collaborative research will, in line with the recommendation form WHO, contribute to a further understanding and the magnitude of the problem with ?missing girls?, as a basis for policies and rising the public awareness of gender inequalities, discrimination of girls and of the long-term societal consequences&#65292;such as high suicide rate of women in rural areas. The project *Dynamics and Consequences of the Increasing Sex Ratio at Birth and the *Missing girls* in China (People's Republic of)* is collaborative research between Peking University of China (People's Republic of) and Nordic School of Public Health in Sweden. The field work had been performed in China (People's Republic of), by Chinese collaborator, Mr. Shusheng Luo, Guided by Swedish researcher Dr. Petra Lofstedt. The following work is paper writing and publishing, and Mr. Shusheng Luo will pursue a doctoral degree at Nordic School of Public Health, Sweden, supervised by professor Max Petzold. This collaborative research will, in line with the recommendation form WHO, contribute to a further understanding and the magnitude of the problem with ?missing girls?, as a basis for policies and rising the public awareness of gender inequalities, discrimination of girls and of the long-term societal consequences&#65292;such as high suicide rate of women in rural areas, and so on. Both PhD Petra Löfstedt at The Swedish Institute of Public Health and Professor Max Petzold at Nordic School of Public Health has had a long-tem collaboration with the School of Public Health, Peking University, China (People's Republic of). This bi-lateral project will definitely deepen the collaboration and communication between Swedish and Chinese institutions.