Before the recent 15th International Aids Conference in Bangkok, Premier Wen Jiabao issued an unprecedented statement that openly outlined China's Aids prevention and control plan. This top-level policy statement is the latest evidence of China's growing acceptance of its Aids problem. Beijing's continued commitment is welcome, but existing Aids control polices often impede effective prevention work among high-risk groups. While needle sharing remains the main source of HIV transmission, sexual transmission stands at 10 per cent, and is steadily rising. The sex industry is seen as the primary source of this increase. If Aids is to be kept from entering the general population, the rate of sexual transmission must be controlled. Current policies leave sex workers socially and legally marginalised, inhibiting the effectiveness of HIV/Aids outreach and prevention programmes. China has an estimated 840,000 HIV cases, of which 80,000 are Aids patients. Since 1985, more than 150,000 people have died. China's HIV prevalence rate remains low, at 0.1 per cent. However, new infections are increasing at a striking annual rate of 30 per cent. The male to female ratio of HIV infections has fallen from 9:1 in 1991 to 4:1 in 2001. Authorities believe the total number of HIV/Aids cases could swell to between 10 and 15 million in six years if comprehensive and proactive prevention measures are not taken. China's sex industry has proliferated dramatically in the past 25 years. According to conservative estimates, there are 6 million prostitutes, and a recent study valued its underground sex industry at 30 billion yuan. The majority of sex workers are young, unmarried, domestic rural-to-urban female economic migrants with limited job and educational opportunities. While women account for 45 per cent of the total workforce, their average annual income is only 80 per cent of men's. In addition, the majority of female sex workers have not entered high school. Faced with gender-based discrimination in the workforce and diminishing opportunities in education, rural women and girls are compelled to enter the sex industry. Sex workers act as a bridge which can channel HIV from high-risk groups into the general population. Shanghai health officials have reported that 80 per cent of females and 20 per cent of males in the city were infected by their spouses. A nationwide survey showed that the majority of sex workers' clients are middle-class men under 35. This trend is likely to increase as China redirects its economic development priorities to its mid-level cities and towns. Prostitution is illegal in China, and given the political climate surrounding HIV/Aids, linking its control to periodic strike-hard anti-prostitution campaigns will remain a mainstay of health and public security policy. While these raids may have positive political benefits, they fail to produce long-term reductions in the number of sex workers or clients. Instead, they force sex workers to become highly mobile and increasingly reluctant to take part in voluntary counselling and testing programmes because they fear the legal and social stigmatising consequences. Beijing should consider decriminalising a regulated sex industry to avert an increase in sexual transmission rates, and thus an uncontrolled explosion of HIV/Aids cases in China. This would expand the social and legal space in which HIV/Aids prevention programmes could effectively operate. Evidence has shown that punitive HIV/Aids control policies are not only ineffective, but also inhibit those who are actively trying to reach the most vulnerable groups. Edmund Settle is programme co-ordinator for the China HIV/Aids Information Network and founder of the China Aids Survey http://www.casy.org