People who attended yesterday's sexology exhibition found sex aids dating to the Ming dynasty, but no modern pornography. Dozens of people, mostly middle-aged and elderly men, attended the adults-only exhibition which is part of the 14th World Congress of Sexology, the first held on Chinese soil. Organisers said attendance had been affected by bad weather. More than 10 booths are selling sex-related products, from herbal spray for male sexual strength to erotic paintings and stamps. About 100 Chinese antiques are on show including porcelain figurines and two Ming dynasty special chairs. Liu Dalin, a professor in sociology at Shanghai University and antique collector, said such treasures had long featured in Chinese culture. 'For example, parents in the late Qing dynasty were shy to talk about sex, so they used porcelain in a shape of a couple making love to teach their daughters how to serve their men.' A 'beautiful lady chair' from the Ming dynasty allowed couples to have sex in a comfortable position. However, the antiques did not impress a Mr Yuen, who paid the $20 entrance fee. 'I'm disappointed, there are no Category III magazines,' he said. The show at the Hong Kong Convention and Exhibition Centre ends on Friday.