The general aim of this paper is to demonstrate the significance of intentional soundscape design in urban squares by investigating people's general perceptions of urban soundscape and sound preferences, and the effects of demographic factors. An intensive questionnaire survey was carried out in two urban squares in Sheffield. Sound identification and classification were both considered. The results show that natural sounds as a group were generally preferred to urban sounds; the preferences of soundscape elements influenced people's choice of using an urban square; and in terms of sound preference, the differences amongst age groups were rather significant, whereas between males and females only slight differences were found. Finally, some suggestions on soundscape design in urban squares are given.