A combination of traditional preference for male offspring, easy access to sex-selective technologies and the One Child Policyhas led to abnormal sex ratios in China. Over the next 20 years it is estimated that 12–15 per cent of all young men in mainland China will remain single and will be unable to have families. The overwhelming majority of them will be of low socio-economic class. This talk will discuss the impact of this phenomenon. It will emphasise concerns about the marginalisation of these young men in society, leading to antisocial behaviour and violence, and threatening societal stability and security.