Focusing on social problems that take place in the public sphere of big city，this study analyzes the spatial distribution of social problems in different areas. The investigation reveals that around the center of the city，social problems in public sphere are as grave as they were，e.g. environmental pollution caused by commercial booths，unruly parking and transgression of private cars，occupation of the sidewalk by peddlers，the annoyance caused by street dancing. About half of the residents keep a negative evaluation about the security of the public sphere. Over 30% of the residents judge the governance of public sphere negatively. The civility and cultural quality of the residents in public sphere and their capacity of participating social governance need to be improved. This study proposes to focus on the public sphere，further build the capacity of social governance，raise the quality of citizens，and advocate public participation，so as to ease the pressure in the public sphere of the downtown.