Previously, the medieval town square or piazza had a function as a place for outdoor living and meeting, a site for market, festival day, and a space for conversation on all topics, dealing goods with each other, hearing the latest news from all over the world. However do we still need public space in the contemporary privatization of life when most of us have private houses or gardens? This thesis is intended to discuss the importance of public space and conclude the guideline for making attractive public space. The Ströget Street in Copenhagen, Demark is observed in order to find out the key factors to the success. At the end, the case of Shanxi Road Square in Nanjing, China will be portrayed and analyzed.